One of the advice I would give is to take a look at the different accelerators - like Y combinator, Starta Capital and many others. The approach I would use:
Why this approach is not bad? Usually the model is already validated it means the audience/market exist (customers pay). You Just think what you can do for the same audience, solve the same problem with different approach (in worse case just copycat)
I prefer looking at US funding rounds for series A or B. These companies have somehow proofen to be valuable.
Thanks for your comment. Make sense :) have any in your mind?)
I think it can be great to get inspiration here, the thing to remember though is that the recently founded Y Combinator companies still have a large chance of failing. They probably aren't profitable yet. That's why I prefer to look at larger funded companies, that already have substantial revenue. Even if they are living off of investor funds, at least they've proven that people will pay money in that area.
You are right. But my idea is different - instead of copying you try to find out what you can do for the same audience as you assume they experiencing the problem other startups solve. Of course this might not work and you can fail like many others. It is happening all the time.