earlygame is harder to explain, with math anyways.
but logically speaking there are a few scenarios
- yasuo wants to push his lane using static shiv - one does not simply turn static shiv on and off and he will get double crit chance from it. And regardless of whether his Q actually triggers it or not which it probably does he cannot farm without pushing harder than usual unless he uses his E but when you've built nothing but attack speed this is unlikely to work out
here's a pro game
https://www.youtube.com/watch?v=is5jgBpXvsk
firstly notice how in the case of ahri she can just line herself up with yasuo and minions and wait on him to dash. He can't completely control his dash range but then he also has to push when he dashes and deal not much damage unless he's built to do damage with E in which case he's probably not gonna have an amazing midgame unless he kills you for some reason. I don't think that even scales with AD
But more importantly, after yasuo gets static shiv shoving is not optional
This one rolls lux of course but the opportunity will still be there regardless off who and how you play even if you don't actually use it.
yasuo cannot turn it off the shove unless he tries to farm with E which is not as safe as it might sound at all but then even after getting fed and shiv proc'ing he's not just instantly clearing waves in the video shortly into the match. He still has to follow up on this to clear waves, its not like its expensive manawise or anything (no mana) but the point is that yasuo cannot just perfect cs safely without wasting cooldowns. In order to farm safely he needs his enhanced Q which can only happen at max every (cooldowns x 3) and to set this up again he must push the lane unless he's getting 3 Qs off on his lane opponent(s) or jungle or something.
Its not objectively a weakness but it is a difficult to avoid playpattern while playing static shiv yasuo
- yasuo doesn't want to push and gets something other than static shiv - Well this one is simple, yasuo now just can't really push that hard. His Q deals 20/40/80/100/120 (+100%AD) its just an empowered autoattack even when he uses the ranged version. He cannot simply instagib a wave with this alone but he can sure as hell push it hard enough that he wont be able to stop it from freezing just outside your tower range which can happen even if you aren't actively pushing under the right conditions. If he gets ganked he can't dash away he can only dash in the direction of the enemy and again its not a controlled dash.
lategame is easier to explain
earlygame = no crit
midgame = easy crit, he will get 100% crits easy
lategame = everyone has crit now but his crits deal 90% less damage... his passive doesn't do anything anymore. Aside perhaps from keeping his build flexible. He is wasting some of his gold if he gets crit items also.
But I'm not an expert so here's some data to demonsrate my point
here it is (ctrl + F "game duration")
look at that thing, it drops like a fucking rock after 45 minutes. But more importantly yasuo only has a 50%+ chance of winning between 24 and 49 minutes and is otherwise useless. What this tells you is that if the game were to accelerate at the normal pace... then it would take about 49 minutes to seal the deal but if you can acquire results aggressively it could tilt him faster. Yasuo tends to peak at 45 minutes. BUT ALSO ONE MORE VERY IMPORTANT NOTE. If yasuo is winning or losing at 49 minutes that means he did the work to earn it from like 30-45 minutes or something. So if his peak winrate is at 45 mins then his optimal gametime is not at 45 mins but rather somewhere around 30-45 mins and somewhere between 34-49 minutes he burns out and just failfishes.
So the evidence very probably supports my claim but then it also appears to give a very clear timeframe as to when yasuo will be strong and when he will not have much positive influence on the game. Its just a matter of determining how long he starts winning before he changes the outcome of the data or basically determining when his power actually peaks and wanes and all that. Again, I'm no expert, it can be 15 minutes 2 minutes or even 20 minutes but he does in fact fall off
for the sake of comparison lets compare his falling off to a classic falloffer
leesin
lee's odds drop 2.5% in a 5 minute range, yasuo comes close
but then lets have a look at some random champs
Ahri
Braum
Cait
Diana
so it looks like yasuo's isn't TOO dramatic but at the same time he has a single peak and never gets back on again like I was saying beforehand.