Lack of cooldowns
Yasuo has a very URF-like feel to him. Rather than "I need to properly time / aim my skills and manage my secondary resource" it feels very much like "It doesn't matter if I waste or miss anything because it will be back up in two seconds."
Uses your minion wave against you
Minions can do a lot of damage early game. Being in your minion wave is supposed to deter enemy champions from attacking you, as they will then take aggro. Yasuo, however, uses your minions to dash around in every direction, not only making skillshots very difficult to land but also making it very easy for him to get in, poke and then get out.
Windwall negates an infinite number of projectiles.
Spellshields block a certain number of skills. Windwall blocks everything. For a rather extensive period of time.
Ult can be procced off of literally everything.
Knockups should be things like a Malphite or Wukong ult, no Thresh's flay or Darius' E pull.
**
Because of his design as a whole, it is less about how good at your champion you are and more about how bad at Yasuo your opponent is.**
With all of the mobility, shields and damage, it honestly feels like you're hoping the Yasuo sucks rather than "I know my champion well enough to play against my opponent.