Tell me one jungler who can duel Udyr?

Exactly. Udyr is king of the jungle (and always has been) because you guys are too busy crying about Lee Sin, Warwick Rammus, etc. But even before everyone else got nerfed, he was still just as bad.

None of these junglers were ever an issue. There's this thing called late game and their late game is not that great. Lee sin has good early game burst, but falls off really hard late game. The utility with his ward dashing never falls off, but this can be countered somewhat by destroying the wards he wants to dash to. Warwick likes to AFK farm the jungler all day, so pressure other lanes while he does this. And Rammus is a tank, and tanks aren't allowed to do damage. If he's really a problem, get null magic mantle.

Lee sin has one trick up his sleeve during teamfights. All he can do is flash behind his target (unless the enemy is REALLY bad at positioning) and kick them into his team. Udyr is god at all stages of the game. He can escape if he starts losing a duel (which should NEVER happen btw) or if he gets mobbed in the jungle (massive MS steroid), he has AOE damage at level 1, and he has a stun. And he can also tank because turtle stance. Udyr excels at everything he does (which is quite a lot) and all other junglers are just a one trick pony (sorry Hecarim).