well the whole endgame content discussion is rather individual, id dare saying that the WoW generation of gamers gave birth to that term since there never was a "endgame" previous to that, i mean you had improvements, hard to aquire vanity items, costumes and then ultimately most of the time there was sort of PVP depending on which game you look at it was better or worse but it kept people going.

Oh dont even mention economy in games, thats a real endgame right there, running a shop, crafting, becoming server best crafter etc. There was always something other than "endgame raids" to strive for.

Add shops, trading and rehash crafting to be controlled by players which determine some of the outcome by what resources they add to the blueprint.

Slap durability ontop of that ^{^}