No one is disagreeing that this is the technical process behind creating a pull request. It just turns out that a number of companies including Github and GitLab are willing to do all of these steps with a few button presses for free for anyone on behalf of any open source project.
I've long felt I was missing something about the github process. It seems insanely complicated to me. Pushing the fork button is a very small piece of the process. Setting up remotes and things is very much NOT button- automated. And at the end of the process, you have this extra repo lying around in your github account that you'll probably never use again. The effort and amount of artifacts generated by a simple change are way out of proportion.
And yes, I do appreciate the rare cases when I can just make the change in the web interface of the original project. But most one-time changes I make involve compiling (or at least running) something.
