I think some of Josh's points apply to all games lately. The "release good enough for now and fix with patches and paid DLC later" is pretty common of many games these days.

For the parasocial stuff, I see some of this behavior in single-player RPGs - with some going insane over voice actors and fictional characters they can romance in them. There was a lot of this in BG3 with certain types of players.

MMOs though are exceptionally time consuming and our patronage is typically a lot longer than any single-player game. Being invested in an MMO does drown out your time for other games, and for many people the thought of playing more than one or two MMOs max is pretty overwhelming.

I do believe the MMO general population is also aging as younger players are into different types of online experiences and they don't have the patience for slower-paced games. I see a lot more older players around than younger ones in some games - especially ESO where instead of 80% of players being in their teens and 20s it seems more are full adults 30+.