I am tired of playing MMOs which force you to level just to get to end-game. Leveling shouldn't be an obstacle. It should be fun and rewarding. If you can't make leveling interesting, don't make it a part of your game.
I played WildStar and ESO when they both released. Both games used the same boring leveling formula with promise of an exciting end-game. Repeating a slight variation on less than six quest types gets boring fast. I don't care how much lore or story you have if the majority of my time is spent gathering <random animal part> that every animal has but only a few allow me to take it. I'm done tolerating annoying leveling grinds just to reach a supposedly exciting end-game.
Trove and Guild Wars 1 have such a fast leveling speed to reach the cap that it almost feels like they skipped leveling entirely. There might be other MMOs in which people can level fast, but please don't suggest them if a first-time player is not likely to achieve the fast speeds you think are possible. For example, I've heard of people leveling in a day or a week in Guild Wars 2, but it takes much longer than that if you're leveling for your first time.