How to fix Yasuo's current state
I've said that Yasuo is balanced for a while, but the meta has shifted over the past few months that has put him above others without directly changing him.
I think an appropriate shift of power would be to lower his Q's AD scaling early until leveled up and require Yasuo to decide between ranking up E and Q for different item builds and early game playstyle.
After this change, it'd be best to monitor his before determining whether or not he is balanced. If he isn't fixed after that, could make his W consume 75-25% of current flow(scaling off level of W) if the bar is not filled (to keep consistency)