By the time anyone here is using slang like “dank”, it has long since stopped being hip. In fact, “hip” is no longer hip.
My kids said dank 10 years ago. It’s a surfer term, a successor to gnarly I suppose. A few years later a local sandwich shop called their special topping “dank sauce”. Now to kids, it’s only their lame parents who use that word. Or Facebook, for that matter.