That is why I love solo, wish it could even be slower since it is way to fast to level. I wish for the old days when it took a few hundred hours of game time to max a character level now it almost pointless to even have the max character level since it takes almost no time to get there.
Part of the reason the End Game is boring is it is too easy and too fast to get there.
Story mode is pointless now since for the most part it is quick bounties to get some mats, gear, and nightmare keys. Then the rest is Rifts and Grifts.
Things are handed out too fast.