It's not that hard, depends on the ADC you're playing. From a Yas perspective, if it's teamfight you have peel and Yas has to go through your whole team as a squishy melee in order to "get" you.... not happening, specially with CC supports. Let's say he dashes through two champs, encounters your Leona, get's stunned in the middle of your team and dies in 2 seconds while his team says "Yasuo mains are cancer" :D. On lane, with you having minions is harder because he has more mobility, but what ADC stands in her wave? You always have more range from the wave.
Let's look at Vayne for example: Yasuo can either dash through a minion to get to your level, dash through you, or walk to you; but unless you're really badly positioned he can't dash through minions to get to you, but if that's the case, then you've already been outplayed. So he has to either walk to you, or dash to you. If he walks to you then he gets free damage as ADC's deal tons of damage, and if he walks he has 4-5 seconds of him taking free damage and he's dead before getting to you. Let's say he windwalls in order to stop the damage, but his windwall goes in front of him, but he still has to walk in front, nullifying his own windwall, he only defends against a few damage. If you're Vayne, you can condemn him if he gets too close by walking and tumble away while still killing him. It's a free kill for you.
If he dashes through you, then you automatically condemn and tumble away, making his dash useless, and he has to either choose to walk to you and die, or take damage while trying to escape(maybe dying).
Same thing with ADC's such as Caitlyn for example, with her dashing away and her traps(if Yasuo gets trapped without windwall, free kill, if he has windwall, he can't attack). If Ashe gets his R he's also dead because he can't windwall. If he ults his windwall, while Ashe moves away, with his slows without Yasuo having dashes he's also dead. Ezreal? He's impossible to kill as Yasuo, he has free flashes and slows(as Iceborn Gauntlet it's a common item), even with minions he's VERY hard to deal with. Graves has a small dash away and a blindness. Corki also has his mobility and his dash away. Draven? He shits on Yasuo, even with windwall he deals a lot of damage, and if he comes melee range Draven can E him. Kalista has dashes so he's kitable. Lucian also dashes away. Quinn? Another ADC that beats Yasuo, Quinn has two abilities that counter Yasuo, his silence, and his E. Tristana can jump away. Sivir? She has no dash away or the like, so she's the more vulnerable one, but she has so much damage that she's no sitting duck. Urgot as ADC? Are you kidding me, he's so strong, cc-like, etc.. even on top he shits on Yasuo. Varus? He's probably the most vulnerable ADC if you as Yas can WW his ult. Vayne? Hardest adc to kill as Yas. Xayah, he's mid-difficulty to kill.
Bottom line is Yasuo needs melee range and only has a single dash. His windwall is defensive but also you need to be offensive to win a trade, because while he can mitigate that damage, he can't attack back. The only way windwall is effective against an ADC is when you're already in melee range, so you can defend against ranged attacks in melee range, while you deal damage in melee range, otherwise you just waste your windwall. The thing is, ADCs got a defense in their kit against assassins. Yasuo is not an assassin, he's a fighter, btw. Riot needs they need a defense against Zed's, Rengo's, K6, etc.. which are the real threats to ADC's. So most ADC's got a defense(jump, shield, dash away, mobility, slows, stuns) in order to defend against assassins, and with them they can create a gap between them and Yasuo.
Does this help?
