I love playing Azir and I still do. Yes, the nerfs in the past has damaged him way more than intended, but he got some of the range back (specifically 375) and a slight increase in his base attack speed. Now, he is sitting around on a 45% winrate and that is a bit below than average.
The main question is...Is Azir viable in SoloQ? Absolutely. Azir is just harder to play than most champions and you must work with your team in order to acheive the best results. I know for sure that he is amazing at objective control and he can make enemies feel like they are entering his territory anywhere on the map. Once you reach late game with Azir, he's literally a bird looking for his prey.
The only main issue that holds me back from playing Azir frequently is the minor bugs that are still following him.