their AR stuff doesn't take off, because they always try to sneak in some registration or subscription to their shady services. when people need an FB account to use a device that can constantly record everything they look at and what they maybe want to use to do NSFW things, they don't want FB to have that info. the only people who wouldn't care are children and it's too expensive and boring for a childrens toy.
I havent looked at sales numbers and dont really follow the industry much but my impression is that the quest was doing really well when it was owned by oculus, and public opinion dropped massivley when meta bought it.