The Hunter's mobility just straight outclasses Titans and warlocks. They can jump out of fov in sticky situations and have an aim-assist breaking Dodge that removes your gamertag as well. Weapons also are usable a millisecond after jumping, unlike gliding warlocks or Titans using lift, with exceptions to a tree of dawnblade and lion rampants. While sure Titans and warlocks have shoulder charge and handheld, do you see them in high level gameplay? They aren't viable options and are easily countered. The hunter can be used effectively in any situation, that's why most unbroken and tournament players play hunters. I know I would be pissed if a hunter jumped on top of me in cqc and one shot me with a melee
Hunters are without a doubt the best choice for pvp, in high rank comp its all you see.