How do you define art? I've always liked Scott McCloud's definition from Understanding Comics: "Art, as I see it, is any human activity which doesn’t grow out of either of our species’ two basic instincts: survival and reproduction."
In my view, anyone who dedicates their free time to creating is an artist.
I am not super familiar with Scott McCloud so sorry for that, but I'm very admirable of comics from a distance.
I think it's worth mentioning I think this might be a little outdated of a definition because philosophy and art is agreeing more every day that everything in art grows out of the survival and reproduction instincts.
They also appear to agree more every day that your last point, that "anyone who dedicates their free time to creating is an artist" holds true.
Consider the question of why humans evolved to make art in the first place, and you'll probably conclude that it was sexual selection. In other words, artists get laid. Though it may be that artists get respect in general, which improves chances of survival in a social species like ours. So I respectfully disagree with Mr. McCloud's definition.
Why reduce all activity to such simplistic motivations? Maybe art is a spandrel. Maybe artists don't get laid any more often than non-artists. Maybe human beings do lots of things that have little to do with passing their genetic material on, because we've acquired motivations that aren't simply reducible to survival or sex. Maybe some of us realized that making art was enjoyable, regardless of whatever reason it arose in the species a couple million years ago.
What then about anonymous artists such as Banksy? Many of the artists we today view as great, such as Van Gogh, were in their time neither respected nor enjoyed financial or, as you offer, sexual benefits from their art. They still pursued it, often into abject poverty and early deaths.
In my view, anyone who dedicates their free time to creating is an artist.