Sorry Riot, but Yasuo is in such a terrible spot there isn't really a way to fix him.
It isn't a matter of a numbers game anymore, he needs an entire kit rework if you want him to be in a healthy position in a meta.
There are plenty of arguments for both unbalanced and balanced in the aspect of yasuos numbers. People say he requires a lot of skill and is in a balanced spot, but there are also plenty of arguments against that.
His central idea is just simply too toxic. Buffing or nerfing him will not and cannot fix any problems and put him in a healthy spot no matter what you do.
The fact that a W can potentially make several champions in a fight be completely irrelevant is absolutely absurd, no amount of number fixing in anything else can fix that.
You can't fix having double benefits from possibly the best stat in the game either, he either will do next to zero damage and make him not worth playing or be absurdly high.
You can't fix the infinite dashes either, having infinite mobility is toxic in every aspect.
Sorry all, but no amount of number changing can fix this.