If you're a substitute janitor, you have a super cool sprite in sun/moon. :P
The postgame is pretty satisfying on and off though. The postgame quest is fun, and you get to catch cool ultra-beasts. The post game competitive, with no bank right now, is essentially restarting trying to do competitive in game, with non-bred pokemon til bank comes out heh.
But it's really not that bad, I managed to get the 20 win streak in the battle tree to get enough BP to get all the power items. Only missing a destiny knot.