Why?
I do acknowledge that this isn't a new phenomena Fischer complained about this before the computer engine era and came up with a chess variant to nullify deep opening prep!
Another change is that territory is more valued than influence now, which too makes games less fun to watch, at least in my experience. To my knowledge, Shibano Toramaru, professional Go player, used to play highly focused on influence, and his games were very interesting to watch; it was just spectacular. But after AlphaGo came he converted to focus on territory like everyone else, only occasionally letting his beast out. But I watched only a few videos on him so don't take my word; it's just my impression.