he is pretty garbage right now. his damage isn't good mid game, (as it should be) but he was also gutted literally everywhere else.
basically its the shurima shuffle syndrome. the shurima shuffle is a ridiculously good combo that when you can do it consistently and on command, its overpowered. it means you have to gut the rest of his kit.
Azir was never intended to be able to engage and also disengage equally as good. Azir was clearly intended to be a super high dps mage who had some tools to outplay his opponent in the form of his shield interrupt/knockup dash and his ult for self peel when someone got in his face.
once they allowed shurima shuffle to exist upon discovery, it allowed for some sick LCS big plays, but made the champion utterly broken.
If Azir couldn't engage or make the big plays, or be as safe as he is with his HUGE escape range, then he wouldn't be so busted. But as long as they support the shurima shuffle, he is going to be gutted.
I say just give him back a lot of his old power and remove the ability to shurima shuffle. (Q while dashing.) if anything they could just slightly extend the range of his basic dash as well.