End game is a lot of things, to a lot of different people.
The thing that sets Glamour apart is that, building up a massive collection of glamour sets requires you to play more or less everything, people who want all the good glamour items will do all the content required to get them.
Someone who just raids at endgame, for example, only really needs to do MSQ to hit level cap and get gear to start on the current raid, then log on once a week to raid (as opposed to WoW's massive time gated mechanics to either slow pre-raid gearing or have a never-ending farming mechanism to keep your damage up with other people)

Someone who wants to collect a ton of Glamour sets on the other hand, they gotta do it all, old content, new content, farming rare drops, pvp, all of it, getting to the "end" of glamour for people who want to keep collecting is a neverending rabbit hole.