I think post game content should still be important, but the common design of having players rush through leveling content so they can run hamster wheel content at max level is terrible. I really wish the whole game was the game, not just the stuff you do after the mind numbingly easy leveling.
As someone who is a little bit more interested in the story, I would love it if games had better story recaps for when you put the game down for extended periods of time too. If it's a game with player choice track the major choices the player makes as well. I restart games so much because I like to jump around between games and then when I get back to some I can't remember enough about what was happening to have any investment in the story anymore.