This is something i think a lot about. I'm a professional artist and so this is my livelyhood but is it all worth it? Would I be happier if I did something else? Probably, but that wouldn't be me so it's kindof impossible to tell.
One thing I do that I find helps me feel validated in the countless hours of art making I've spent is that I try to focus on illustrations that are really important to me. I'm lucky in that I "got good" early and so don't have to "waste" time training later in life. I can get right to illustrating and my time is rarely wasted as a result.
But still, is it worth the time investment? Generally yes. I can make things that no one has seen before and bring my imagination to life/express myself in ways few people can. I don't know if that objectively translates to "time well spent" but it does feel like it at least.