>Art is meant to be [. . .]

There are literally thousands of years of texts, debates, classes, hell, entire schools based around those first five words.

You simply cannot use them definitively. It's just not that simple.

I can think of lots of art that are designed to, if not crush the humans spirit, at least call into question the goodness of it. See "Rhythm 0" by Marina Abramović or “Helena & El Pascador” Marco Evaristti are just two examples.

Nah, I don't think this is the take generally.

There is art that crushes the human spirit. Art about war. Art about slavery. Art about personal trauma. I think if we only depicted pretty war, pretty slavery, pretty rape and genocide, that's pretty disgusting.