I'd argue that endgame as it exists in current MMOs blows--and the satisfaction of leveling and grouping through level cap is much more appealing and offers a lot more flexibility, growth, and fun than grinding out the same instances with 20-40+ people you don't know. Endgame will not always suck. It'll just take devs coming up with something more inventive than following the blueprints of what has passed for "endgame" for just shy of a decade at this point.

Endgame today annihilates any sense of the RPG in MMORPG, turning what was once fun into work. I'm willing to bet no one's gonna show us any different until 38 Studios or CCP's next MMO start breaking the rules a bit. They are the only two companies I can think of off the top of my head that will have the resources AND the creativity. Every other MMO developer at this point only has one or the other, IMHO.

Everyone else is too fat and content and has a consumer base who more than willing apparently to feed on yesterday's cold leftovers.