The Mythic+ system could quite possibly be the most terribly implemented WoW system of all time. We are over one year into this expansion, over 100 item levels higher than launch, doing many times more dps than launch, have fully fleshed out artifacts, yet we are still struggling on the same keystone levels as we were at launch.
It makes absolutely no sense. The scaling the HP of these dungeons has been inelegent, lazy and uninspired. And worst of all, it's demotivating to know that your progress is being stripped down every patch.
I really hope that the Mythic+ system is either completely revamped or better yet scrapped for 8.0. Because people are not going to stick around for another expansion of constant HP buffs to dungeons every patch just for the sake of buffing them.