Ask yourself when you pick up a hobby: Are you in the top 10% in the world with that skillset or do you have the time and energy to be good enough to do it for a living? No? Then it’s not worth it to do it for the money. And even then, as you said, it’s more about marketing (i.e. you’re not that great but can be successful if you get a big enough following). And marketing is a whole different beast.
You can also think about the potential income stream just as a bonus that you don’t care if you get it or not. I make non-mainstream music and don’t really have the energy to market it, so I just post it where I can and hope people see it. I’ve earned $350 from streaming in 4 years. That’s not life changing money, but it’s a nice thing to have that I wouldn’t really care if I didn’t get.
It’s both art and content for me. I listen to a very wide range of genres; from metal to jazz, EDM, prog, industrial, film scores, kpop, and more. Streaming platforms have a hard time profiling me just based on the stuff I listen to.
I’m also a musican, so it’s my “art” as well, because I create it to express myself. It’s been a huge part of my entire life.