to have designated places in a city where people can be messy like a gum wall. A gum wall doesn't appeal to me but it seems like it could fill a human urge without really hurting anything.

In some cultures (greek?) breaking plates is a thing. No idea why but it is. Just as putting gum on a wall might provide some satisfaction to some throwing glass at a wall might be appealing. You could have a designated area outside of a bar where glass could be recycled and people go get some sort of enjoyment from breaking glass ( I thinking along the lines of axe throwing ). Take the broken glass and find a good place to dump it in the ocean or recycle it in some other way.

I'm not in anyway a glass expert or glass recycling expert but it seems to me with how environmentally focused California is that if the glass beach was some sort of environmental issue it would've been cleaned up by now.

It seems to me a environmental safe way to recycle glass could be to find a secluded beach and let the ocean break it down over time like the place in CA did.