Art with any reach can't "mean" anything because that would inevitably lead to art that means "capitalism needs to be destroyed". So we have this horseshit or abstract art that's just shapes and bullshit.

Edit: just to be clear, there's plenty of modern art I like that is actually good. This exhibition at MCA Chicago a few years ago is one of my favorites ever. But the messages one would take away from this about the internet and the modern age--about the alienation, the ennui, the chintzy fakeness, the commodification of every aspect of our lives, down to turning our very identities into a fucking brand--would lead any serious person to deeply questioning why things are like this and how we can change them for the better. And that's why most modern art isn't like that, and is mostly dumb finger paint nonsense that means nothing.