How do you folks do find next niche product to work on?

So I have a bunch of random ideas, but nobody would use them because, of course, these ideas like I am creating new problems for me in my mind and trying to solve them.

But I want to hear, like if you are an indie hacker, how do you plan to research the niche and also analyse competitors and time estimation for that product?

So basically, before starting a SaaS, what do you research, and do you keep any backup plan and some kind of strategies as well, like when you would pivot?

Because I have tried to launch multiple products, but blindly starting to work on a new SaaS sounds dumb to me, that's why.