Art is a form of communication. Modern art tries to explore new ways to do this. This can take the form of viewing common things in a new light. E.g. the soup cans. It can also deliberately be abstracted to absurdity. E.g. using paint splatters in an attempt to express pure emotion.

A child's stick man drawing takes relatively little skill (for an adult) coming from a small child to a grandparent, it communicates so much more, and can be treasured accordingly. The skill isn't a critical bit of art (though often important, the communication is.

AI slop cuts that line of deep communication. It also poisons the communal trust in the value of that link.