Artificial Intelligence has been heralded as the future of software development, promising to accelerate coding, reduce errors, and even replace junior developers altogether. Investors pour billions into AI coding assistants, and many believe these tools will soon revolutionize the way we write software.
But a new study by the AI research nonprofit METR throws a wrench in this narrative. Published in July 2025 and recently covered by Reuters, the study found that experienced software developers actually slowed down by nearly 20% when using AI coding assistants on tasks involving codebases they were intimately familiar with.
This result surprises many who expected AI to supercharge seasoned coders, but it shines a light on a fundamental truth: AI coding agents are not ready to replace human developers at least not yet. In this article, I’ll explore the top five reasons why AI agents still fall short of fully replacing human developers, drawing on the METR study and broader trends in the industry.
1. AI Suggestions Often Require Careful Review and Correction
The METR study’s key finding was that AI-generated code suggestions, while often directionally correct, rarely matched exactly what the developer needed. Developers had to spend extra time reviewing, editing, and correcting AI output before it could be merged into the codebase.
In one sense, this is understandable code is precise, and even small errors or mismatches can introduce bugs or unexpected behavior. But the result is that instead of speeding up development, the AI assistant adds an additional layer of verification and debugging that experienced developers can find frustrating and time-consuming.
This slow-down effect is most pronounced with experienced developers working on large, complex, or legacy codebases where intimate knowledge of system quirks and constraints is essential.
In my own experience, AI suggestions were often irrelevant and I would end up pressing Esc key multiples times to cancel the suggestions.
2. Experienced Developers Value Understanding and Control Over Speed
Why would experienced developers continue to use AI tools despite the slowdown?
The study authors observed that many developers liked the AI experience because it made coding feel easier and less effortful, even if it took longer. One participant likened it to editing an essay rather than staring at a blank page.
For seasoned coders, the key is not just finishing tasks quickly it’s about maintaining deep understanding and control over the code. When working on a familiar project, developers want to know exactly what each line of code does and why it’s there.
AI-generated code, by contrast, can feel like a black box suggestion developers need to double-check it, refactor it, or reimplement parts to align with their mental model. This leads to more time spent but arguably results in better quality and safer code.
3. Agentic Coding is Still Inefficient and Error-Prone
“Agentic coding” refers to AI systems autonomously writing, debugging, and designing software with minimal human oversight. While this idea sounds exciting, current technology is still far from this ideal.
Most AI coding assistants today, including popular tools like Cursor, GitHub Copilot, and others, operate more as assistants than autonomous coders. They excel at generating snippets, autocompleting code, and automating repetitive tasks, but cannot reliably build complex features or systems on their own.
The METR study underscores that true autonomous AI coding remains inefficient and error-prone, requiring constant human intervention to guide, correct, and integrate AI suggestions.
4. Human Creativity, Judgment, and Context Still Matter
Coding is not just about writing instructions that computers execute it’s a deeply creative, iterative, and contextual process. Developers make architectural decisions, design APIs, and solve ambiguous problems based on business needs, user experience, security, and more.
AI lacks the nuanced understanding and ethical reasoning humans bring to software development. It does not understand company culture, customer preferences, or emerging trends unless explicitly programmed.
Thus, human creativity, judgment, and domain expertise remain irreplaceable in software engineering, at least for now.
5. AI Tools Are Great at Automating Repetitive Tasks — Not Replacing Developers
While AI hasn’t replaced developers, it has proven extremely helpful in automating repetitive, low-value tasks that eat up valuable developer time.
One example is documentation updates, a notoriously tedious but crucial part of software projects. Tools like DeepDocs automate the process of generating, maintaining, and updating documentation directly from code changes or developer comments. This allows engineers to focus on writing code while keeping docs in sync.
Similarly, AI assistants can help with code formatting, refactoring suggestions, writing boilerplate code, testing automation, and more all tasks that free developers from mundane work and reduce cognitive load.
What This Means for the Future of AI in Development
The METR study’s findings highlight an important nuance often lost in hype-driven narratives: AI is not a magic bullet that instantly makes all developers more productive.
Instead, AI coding tools are evolving into collaborative partners that support developers rather than replace them. The slowdown experienced by seasoned developers is partly due to the current gap between AI-generated suggestions and the precision required in complex real-world codebases.
But as AI models improve, and as tools integrate better with developer workflows, we can expect these assistants to become more efficient and reliable.
How Developers Can Make the Most of AI Coding Assistants Today
Despite the current limitations, AI tools are here to stay and can be powerful helpers when used thoughtfully:
- Use AI to automate repetitive tasks such as documentation, testing, and boilerplate code generation.
- Don’t blindly trust AI suggestions always review and test AI-generated code carefully.
- Leverage AI for brainstorming and prototyping, but keep critical design and architectural decisions human-led.
- Integrate AI tools with developer documentation and knowledge management systems to improve context and reduce errors.
- Stay patient and provide feedback to AI tool developers — your experience will shape the next generation of assistants.
Conclusion
AI is reshaping software development, but it’s clear that we’re not at the stage where AI agents can fully replace human developers — especially experienced ones working on complex codebases.
The METR study’s surprising result that AI can actually slow down seasoned developers reminds us that software engineering is a deeply human craft requiring creativity, judgment, and careful oversight.
That said, AI-powered assistants like DeepDocs that automate repetitive tasks show us the real promise of AI in development: not replacing humans, but empowering them to focus on what matters most.
As AI continues to evolve, the future will likely be a partnership developers augmented by AI agents combining the best of both worlds for better software, faster and safer.
Top comments (4)
I think as long as we know when and how to use AI we'll be productive. Nice Article
Totally agree with this. AI is getting better, but there’s still a huge gap when it comes to context, creativity, and just… knowing what actually matters in a codebase.
We’ve been working on ways to make AI more accountable, not just smarter. One of the things we’re exploring is letting AI agents run fully on-chain so their actions are transparent and verifiable. No black boxes, no guessing.
Still a long way to go, but it’s exciting to see tools shift from "replacing devs" to actually supporting them better.
Curious how others are using AI in your own workflow, what's been helpful vs just hype?
This article is incredibly relevant and sparks a great discussion, doesn't it? As a web developer who almost daily interacts with AI as a "colleague," I completely agree that, for now, AI can't entirely replace our role. The points raised in the article about nuance, creativity, and even social interaction are very valid and directly resonate with what we experience in the field.
A prime example is when we're dealing with requirements from clients or the product team. Often, they don't articulate their requests in precise, technical language. There are many implied details, unspoken expectations, or even scope changes midway through. Now, AI, no matter how sophisticated its algorithms, still seems to struggle with grasping these non-verbal cues or subtle 'feelings.' We, as humans, can adapt, negotiate, and sometimes even 'read the minds' of users or stakeholders to create solutions that are truly spot-on and effective, not just 'correct' in terms of code syntax. That requires intuition and empathy that AI simply doesn't possess yet.
But that's precisely where the excitement lies! I don't see this as a permanent limitation for AI, but rather as a significant challenge and a golden opportunity for us and for the very evolution of AI itself. AI's development is incredibly rapid. What AI "can't do" today might no longer be an obstacle tomorrow or the day after. Just think, a few years ago, we probably never imagined AI could generate realistic images or write essays as quickly and proficiently as it does now.
So, instead of viewing this as an AI deficiency, I see it as a transitional phase towards much more advanced and integrated AI. Perhaps in the future, AI will learn to "read" context even better, or even be capable of brainstorming more revolutionary ideas. Of course, our role as developers will evolve. We might no longer focus on coding from scratch for boilerplate tasks, but rather on guiding AI, designing complex architectures, and solving problems that genuinely require that touch of human creative and strategic thinking.
I believe AI is not a threat, but an accelerator. It will continue to be a tool that makes us far more productive and capable of creating works that were previously difficult or even impossible to achieve with such incredible speed. This is precisely the time for us to keep learning and adapting so we can 'ride' this wave of AI development, rather than being overwhelmed by it. Isn't it fascinating to imagine how the future of the developer profession will be shaped by this collaboration?
I fully agree with your article. In its current state, AI is, I would say a highly advanced version of Google Search, plus a writing tool that helps out here and there. Replacing humans entirely with AI still feels like a distant reality. Although, one thing seems certain: Google is likely to see a significant decline in both relevance and revenue pretty soon.