Absolutely. But OP is focused on getting good projects for the developers and usually the devs saying they can't find customers are in locations where the COL is too high for this to be profitable for them.

One to get around this problem is to focus on only doing the same kind of work and getting better at doing it quickly so it becomes profitable to you, or doing it in a more Productized Service fashion. But that's a solution to a different problem, not what the OP was asking about.

This is huge, and what plagues a lot of software engineers / product developers to this day. You may find a super cheap software company somewhere out in the world - but if the project is anything more than something like a webpage with jquery (as most modern projects involving software are) you end up spending more on fixing, re-fixing, and billing than you would have if you had just paid one time for the more expensive company / service / consultant that is well vouched for or acreddited

Sure, this is absolutely true. That said, if you can test a prototype for $100 and validate the business idea it's easier to figure out how to pay for (and/or that it is worth spending the time building yourself) the better, built from scratch version. You'll probably also get some good feedback.

I think this is the disconnect for me when reading this question. If the question is "where do I find good ideas for my personal tinkering projects" that's one thing, but if you're looking for profitable startup ideas it's not about the engineering - it's about testing quickly and validating the business so the development piece can be much less important (unless of course the business is software tooling)