Why is Yasuo allowed to be overloaded as he is?
He has Damage and Tankyness with his passive and w. He counters all ranged abilites and AA with his w. He has incredible DPS and Burst damage. He has the hardest cc in the game on a potential 30 sec cd, no cooldown infinite dashes on his e. He has double crit chance being the only champion to get 100% crit chance with 2 items next to tryndamere which has a lot more weaknesses. Yasuo is unkitable but godlike at kiting himself.
So Azir was nerfed into oblivion for being overloaded. They say he did too many different things too. And the worst of those things was his high damage at high range.
The difference is that Azir catches up with Yasuo's Damage at 3 Items. Effectively his Zone Potential is a lot lower than Yasuo's through his infinite dashes.
Yasuo can also push as fast as Azir.
Lets compare the abilites.
The Passive is clearly better on Yasuo because Azir's Passive is very situational and has little impact besides buying time. The Q Ability is even, Azir's Q has more Range, Yasuo's Q has his tornado. I would even give that Point to Yasuo because of the knock up but lets say its even though Yasuo's Q Range can be increased thanks to his e. The W Ability gives Azir Zone, enhances his AA and synergizes with his Q and E. Yasuo's W denies every single projectile for at least half of a team fight. Even again. Azir's E is useless compared to Yasuo. It has a significantly long Cooldown with a higher Range thanks to his Q increasing that Range a lot. Yasuo just needs a minion Wave to cover the same distance. On top of that Yasuo has a lot more movement speed than Azir which allows him to catch up or close distances a lot easier.
Azir's R is a wall that knocks enemies away and up if they dash onto it. This is mainly used for self protection and protecting other carries. Yet again it lasts only for 2 seconds which is not even half a teamfight. Yasuo's R in contrast to that has a very low Cooldown, can potentially knock up up to 5 enemies and deal tons of damage. On top he gets his shield reset and gets free armor pen. Yet again landing the Q is not the easiest task but it gives potential high impact on skilled players.
The only Reason Yasuo is not nerfed to oblivion is that he is not picked in competitive League of Legends because his weaknesses can be exploited in organized teamplay which only happens in High elo or competitive play. So technically Yasuo is a useless champion created for noob bashing only :D
I just realized I answered my question myself:D