Yasuo does has a strong early, mid, and late game
but, like many squishy melees that deal sustained damage (
), he is feast or famine. Sure, if he's even on farm and kills with the enemy carries and finishes his core without falling behind, he's going to have a strong mid and late game. The moment he's 0/2 and 20 cs behind, he will get blown up before he even gets in range to deal damage. As a frontline squishy that's extremely vulnerable to hard cc, there's virtually no way to comeback if you get significantly behind with the exception of a lucky ult.
. To top it off he has one of the best combinations of defensive abilities in the game (a decent personal shield and a shield that can protect him and his team from all projectiles and there are a lot of them). Sure the CD is decent, but as he ranks it up the windows go down. His kit needs bigger windows really. From his ult being on almost a 30s CD late game to his ability to infinite dash. I personally think he should spend his flow for wind wall or it needs to actually spawn in a set place and not instant spawn and drift forward. And then maybe look at nerfing his MS to 335 and removing his wind wall giving vision.