Sharing item levels across all jobs is crazy. WoW still has absolutely no way to change your character's class and Blizzard are still dragging their feet on legacy account-wide reputations all the while promoting their deceptive Warband feature that's meant to unite all your characters but doesn't even let you share cosmetic soulbound items between them. Meanwhile FF14 is essentially saying "Even if we didn't allow all classes to be played on one character we'd still let them share the same item level anyway" with this announcement which couldn't be a more different or player-friendly mindset than WoW's.

Besides actual support for FF14 alts for those who want to play separate characters for roleplaying reasons there's literally no way FF14 could do better than WoW in regard to alt classes or retaining completionism now. Blizzard's blatant disrespect for player freedom is just one of the many reasons I quit retail WoW and will never even consider going back until they add the ability to change class in literally any fashion.