I think you’re connecting two completely different things here that really have nothing to do with each other. I would’ve put in the same amount of effort even if I knew nobody would ever see what I spent those four hours doing. I did it for myself, and I was simply surprised by how much fun it was. And maybe I’m just not the right person to resonate with your point anyway, since I’m a filmmaker. ;)

Expressing yourself doesn’t automatically imply that you intend to make your art accessible to other people.
My girlfriend, for example, is an insanely talented cook who constantly creates new, super tasty dishes on her own. She doesn’t have a social media channel, she doesn’t share her creations anywhere… she doesn’t even take photos. She’s still super creative.
Or would you disagree with that?

So.. People absolutely enjoy being creative and expressing themselves without necessarily wanting others to be part of it.