Questing, dailies (leves) and grinding are not even enough.

We also need the ability to level with dungeons only and public questing (the behests before the party size nerf) only, if we want to have more than the average current game.

Rift, for instance, has questing, public questing (rifts), grind and pvp. I'm pretty sure WoW has at least 4 ways to level too. Etc.