alt Hacker Newsartists dont do "normal" and generaly experience reality from a particular, and personal point of view, and grocerie store managers and young artists will almost certainly have mutualy antagonistic points of view. artists thrive in random spontainious environments, but forget about food, so we give them money, that they give to normal grocery store clerks, and we all forgo the seething frustration that would result from your suggestion.
What I see among artist friends, they have no problems holding a job. But their art is not exactly „bill-paying“. It's not bad, it's just not commercializable mainstream. At best it covers their expenses for studios, equipment and so on.
For that crowd, money for 3 years is not really interesting. It would ruin their existing (smaller or bigger) non-artsy careers. But their art, without significant mainstream changes, has no chance to cover a living. Even after focusing on it for 3 years.
I don't see a point to give such crowd a free ride either. They're fully capable society members. I don't see a difference between such artist getting a free ride vs me getting free money to ride my bicycle because I'd maybe do some cool shit if I had more time. Or maybe I should get a handout to do some opensource? Code is also art anyway.