The least competitive markets are most likely local small-businesses with regional restrictions. By this I mean places that where you need to physically go (e.g. dry cleaner) or where someone needs to physically come to you (e.g. electrician). Because you're only competing with people in a specific region, these are going to be much less competitive than industries where you compete with the whole world (e.g. software).
This doesn't necessarily help you come up with new software, but it is something I've spent a lot of time thinking about since I'm also trying to start a business.
I would pay handsomely for a service that would find and dispatch a qualified tradesperson (electrician, residential HVAC, plumbing, &c.) that would show up when promised and get the job done. And would guarantee the work, pull permits, and get me a lien waiver afterwards. I really hate the time it takes to wade through online reviews, play phone tag, and deal with flakes and no-shows when there's something that needs to be done around the house.
For those tradespeople, running a small business can be seriously time consuming. I try to support lone tradies or very small business people, but it's almost always easier finding slightly larger ones that have enough staff that there is someone handling quotes and delegating tradespeople.
I'd suggest building a backoffice for tradies that automates as much as possible. Payments, chasing payments, reminding them of people waiting for quotes, etc. A CRM app that all their incoming enquiries go directly to, etc. Otherwise they have quote requests coming into their phone messages or emails and getting lost along with everything else. I run a small business and have 200-500+ unread emails at almost any time. If something slips off the first screen of G-Suite, it is much harder to remember it.
Something like this has been a business idea I've been sitting on, but it's hard to get started (chicken egg, have to get enough customers AND tradespeople for it to be worth either's time), and could be capital intensive.
I figured it's actually easier to sell this service, at least to start with, to small and medium sized businesses which don't need fulltime staff for some trades oriented work, but have enough of that kind of work for it to be worth setting up a business relationship. But of course the issue with this is it's just a small business idea - you'd need to figure out how to add value to differentiate yourself from the thousands of contractors already doing this if you want to scale beyond the lifestyle level.
If you want quality you usually contact a business that has gained a good reputation, not an individual person. They usually charge more and have a big backlog spanning multiple weeks but the people they send are highly qualified.
That backlog is absolutely necessary for the business to function though. Without the backlog there is idle time and since professionals work for a salary that idle time has to be paid for by passing costs onto customers.
Yes, but most of the time companies that run those review sites don't care. To make difference you would have to check people on your own and that does not scale. Doing stuff that does not scale might get you a decent company but you are not going to be unicorn. Unfortunately a lot of people aim to go to the moon instead of having both feet steady on the ground.
This doesn't necessarily help you come up with new software, but it is something I've spent a lot of time thinking about since I'm also trying to start a business.