People will keep telling you find problems problems and problems. Well, if you could do that - which is the most obvious thing while looking for a project idea - then you wouldn’t be asking it here anyways. I find it quite useless advice when someone tells me oh solve your own problem. Like, how I couldn’t think of it!

Imo, best is to read and read. Read online communities like this one, indiehacker, Ph, write down every idea that you spontaneously find and think that it might be something.

Also, if you would like to earn money without spending much on marketing and spending time on community building then it makes sense to focus on B2B models. However, this also comes with its own problem like how could you possibly know about a niche business market. In the end, you are a developer. In this case, it is better to find small businesses around you who would be willing to work with you and would need your product d right away. You could build some mvp with them and pick it up from there