Running out of stuff to, there needs to be more endgame content.

[Tupsi]

This is a serious answer. This is not sarcasm nor an attempt to mock you. If you have done all of those things by now, here's my advice:

Play another game. Seriously. No matter the quality of a game, if you grind it to the ground with too much playtime, you WILL get bored, that's how human beings are, repetition produces boredom. You should change it up once in a while.

And when 2.1 comes out, I suggest you don't burn yourself out, because you will be short on content rapidly.

Yoshi himself said The game starts once you reach end-game - which means in all reality they should have focused more on end-game content.