I don't even consider Yasuo to be anywhere OP, he's just very obnoxious to play against. With all his dashes, windwall and free shield, he's like a very annoying mosquito that you're trying to unsuccessfuly swat.
Adc on the other hand, have completely shifted the current meta. Ninja Tabi and tanks shine right now because they work well against/with adc. Adc often deal as much/more damage than melee classes and assassins, which is very wrong.
If you look at the archer class from a tabletop rpg, it is never meant to deal as much damage as a melee class like a fighter, but their relative safety and ranged attacks allows them to dish out a reliable amount of dps with a very high uptime (while melee class actually need to be in their target's face to deal any damage) which allows them to deal more overall damage than melee classes despite their lower dps. The same could be applied to LoL, but then Riot buffed adc itemizations and the class that was meant to babysit them also became much stronger, which threw the balance off and made the ranged class into the most important part of the group, with the meta shifting around them.