The actual sticking point is that nobody actually wants "ready player one", even people who think they do.

VRChat and RecRoom exist today and are available to anyone, anywhere with an internet connection. They do not have millions of players because "meet strangers in a virtual environment that can be ANYTHING" is a novelty, not something you want to do every day.

I say this as someone who literally spent hours every weekend during the pandemic raving (yes really) and socializing in VR chat. Your average person doesn't want to be spammed with half naked Anime Waifu avatars and dinosaurs with boobs