Ok I agree that Yasuo's double crit and shield are toxic mechanics.
They should be removed and replaced with something else (like more team utility) to compensate.
Passive: Remove shield and double crit chance. -New Passive- : Yasuo's critical strikes deal true damage instead.
Wind wall: -More team utility- Allies that cross the wind wall receive 10/20/30/40/50% movement speed and a wind shield for 3 seconds. The wind shield blocks all projectiles that would hit the champion.
Last breath: Instead of armor penetration his attacks will deal on-hit true damage equal to 5/10/15% of the target's maximum health for the duration.
Those changes will remove the toxic aspects of his kit and will separate good yasuos from great yasuos!