They didn't improve the graphics because it was planned as a PS4 game. Also, the Atreus section wasn't done that way to increase the length lol. It was to make the players get attached to the character which obviously backfired.
I logged into try some multiplayer with crossplay off from Xbox system settings. Matchmaking took about 2mins rather than 10 secs normally but i was able to find players. Only played 3 matches though.
I deleted the campaign and keeping zombies and multiplayer installed on HDD.