What's Wrong With Yasuo?
Nothing, by far the most balanced champion in the game.
Okay, but seriously, let's really talk about the state of the champion that is Yasuo. I wanted to make this discussion, because I tend to be pretty biased and would like to have a civil discussion on such a extremely hot topic, I mean we're talking surface of the sun levels of hot. So let's begin shall we?
Let's start with the obvious and point out that Yasuo can be stopped from becoming the late game monster I've personally seen him become, seeing as if he does become fed, and you're team has CC, he should become the main focus of team fights. This is mostly the problem that I see in low elo, is that when Yasuo becomes fed, some times teams don't instantly focus him. Which allows him to pick off your back line and become an even more pain in the neck. With that said; however, he does tend to have some pretty powerful item spikes during laning phase, now while it is true that making it harder for him to buy his first item, whether it be a PD or SS, should stall him out long enough in order for the rest of your team to not see him as a threat. But, and I can hear people saying it from the back row, "All he has to do then is sit and lane and free farm till he gets his first item!", this is also true and at this point in time you have two choices as his enemy laner. Either 1) Stay in lane as long as he stays in lane and keep crapping on him or 2) Leave the lane in order to help your team, which allows him to farm, which allows him to hit his power spikes. Both choices should be fine in retrospect considering option 1 keeps him at a very low gold income making it harder for him to get back into the game and option 2 that you've actually managed to stall him out long enough that his power spikes shouldn't be all that impactful. Let's actually focus on that, because there are some games that, mind you this is in Bronze, I have seen a 3/8 Yasuo farm long enough to get the items he needs and just start sweeping my team. I've also seen from myself from playing him that if you allow Yasuo to keep farming without punishing him he will start to matter in team fights.
Basically the first half of this is supporting both sides of the Yasuo argument, that he can easily be shut down into nothing, but if left unchecked he can rally and start doing damage.
I think the problem may stem from the items he builds and his passive Crit gain. Now I'm not saying get rid of his extra crit bonus or his passive shield those are actually important to his kit, dueling power, and survival. No, I believe his Passive may need a nerf and I will explain why. Basically old crit items gave less Crit Chance, which meant Yasuo had to either bring Crit runes in order to hit 100% crit chance or build 3 items in order to get the crit and damage. Now new crit items have higher chances allowing Yasuo to get to 100% and damage with 2 items in the early game, giving him a massive power spike that most tanks can't handle, even with a Randuin's item rush, seeing as PD is 2600g and RO is 2900g. Let's not forget to mention that PD, or SS, and IE are almost always the first two items rushed. Going against ap? PD, IE. Going agaist fighter/bruiser? PD, IE.? Going against range that can outpoke him? PD, IE. Those are his go to items for almost every situation and once he's done building those two items that's all the crit he needs the rest of his items will either be damage or defense. ADC's need to at least build 3 crit items before they start doing damage that matters in team fights and most of the items are from the Zeal build line, which doesn't leave much room for extra damage.
So, I propose, instead of nerfing the Zeal items, which would be a terrible idea by the way, I suggest we nerf the amount of bonus crit chance that Yasuo receive's from building crit, instead of Double, which is 100%, we try 50% first, if that is too hard of a nerf, then we can try 75%, basically we want a happy medium when which Yasuo can still become a monster late game, but his early needs to be a tad weaker, forcing him to at least build three crit items before his insane power spike. Also might want to look at his Passive shield, maybe add more value to how many units he needs to walk in order to fill the bar up. I would say add a like a 5 sec timer to it, but I believe that might be a bit overkill considering that Yasuo does have to move around in order to fill it back up.
This is just my idea on how to balance Yasuo, mostly from a Bronze player point of view. And maybe I'm wrong, hopefully there is more constructive criticism other than, "OMG, learn how to lane against Yas, you Bronzie".
TL;DR Yasuo is both easily countered and a late game monster Most of his power comes from his first two items that some champs can't handle or survive Once Zeal items were buffed, Yasuo's Passive should have been nerfed. Nerfing his passive bonus crit chance to 50% or 75% could lower his early game power forcing him to at least build 3 crit items Making it to where he has to walk a further distance for his passive shield to come up Don't hate me for my opinion, even if I am Bronze.