To answer your question, if you're looking for a cool business so you can do what you want that is great and if you're looking for "meaning" that might be something else. There is no way that I would presume to tell anyone else what they should find meaning in. If a family is not what you find meaningful, then you're a person and that's your entirely legit decision.
So:
A) the question is what projects I personally find most rewarding (not what projects I think other people would find rewarding),
B) the echo chamber response is resoundingly "my tech side project that I make little money on" (good for those folks, I sincerely am sure they love their families too, even if they feel like it's better to serve them through employment... heck, playing music with my buddies is very similar),
C) the OP's favorite part of being a developer is "when you solve the problem and make their life easier, even if it was easy to solve. I'd love to find something where every day was like that!" and I don't feel like something along the lines of "perhaps directly caring for the humans around you" is a crazy, out of context, hippy dippy answer.
I hope that doesn't sound like either a "defense of familism" or wear you out... it's just my own lived experience and I am sharing it because it's been helpful to me. I don't expect you to agree.