First of all, I really like how you worded your post in such a way that anyone who tries to give any actual commentary on yasuo balance will be labeled as a yasuo main and therefore have their opinion voided.
Secondly, yes, I am a yasuo main, get it out of your system.
Thirdly, with Stattik Shiv and Cloak of Agility, yasuo does get 100% crit chance. However, with how his kit is he does around 210 damage per auto with said 2 items. That is actually only slightly higher damage than an adc would at 2 of thier main items completed, and they have the benefit of range and a lane buddy.
Fourth, The mastery that "pretty much is free life steal" only activates when he crits a champion. Meaning, he has to be in melee range, in order to get his free lifesteal. Think about that for a sec.
Fifth, His shield can be brought down with literally 1 instance of damage from any champion source. You can hit him with the extra aoe from Ludens Echo and bring down his shield. So what exactly is the problem with it?
Sixth, His E. Yes, it does give him alot of mobility, around enemy minions. Know how to rob him of that mobility? DON'T FIGHT HIM IN YOUR MINIONS. Bring him to the river, bring him under his turret, fight him in the jungle. Literally, the stupidest thing you can do, is fight yasuo in an area where he has the advantadge. It's like farming against a shen under his turret. You are literally placing yourself in danger