I suppose almost everyone asks questions of this nature. There's is a part of us that questions things, and maybe that is a part of being creative. Maybe the hope of creating something, in this case, a song, that might lead to a since of permanency, legend or the like. An artist may be driven like this, not like it benefited Van Gogh much when he was alive.
I started writing music in the seventies with a buddy in college. We wrote a lot of stuff in the 80's, had a band, played, broke up, moved on, worked day jobs, marriages, kids, etc. I went back to writing in 2017, met another cool musician near by, made a YouTube, got lots of hits, got played on LPFM radio, and now I'm a "songwriting junkie." Lol. Just finished a new song this week which I had been working on for a year maybe on and off, going to do the rough recording tomorrow, then we're gonna do a video and enter NPR's Tiny Desk Contest again. It's not for money with me, it's "Maslow's Hierarchy of needs." Where's Sig when we need him?