This meta is crazy AF. Need some explanations, plz.

I literally had 200-300 armor XD. And i felt like k had 50. Why can a tanks get oneshot xD? Máster yi just jumped to me (Ornn) and killed me in 2 seconds, Next Game tryndamerde killed me with 4 autos as (Taric top), and then a yasuo, god.... What the hell is that dmg? Is armor useless, or am I crazy? U get 300 armor and get bursted instantly anyways, u get hexdrinker and Mercury, and become almost inmortal against a mage (Trust me, i hace experience in that). I've never played any kind of mages, but i honestly think they need some help, and the AD bruisers Who can just spam conqueror Infinity edge, need a HUGE change, because its not normal, to get almost oneshot against a yi who isn't even feed. And What happened to botlane? Why is nobody picking normal adcs? I only ser yasuos irelias and Even Brand as adc LOL, im not talking about low elo, im talking about plat-diamomd games, the damage in games are insane, is sick, my games lasts like 20 mins, or 10 if my team procced to open mid.. Can't get to late Game, it's imposible, stomp them, or get stomped, that's basically all my games, i tries my hard, but there's NO WAY to comeback anymore, once a yasuo gets fed he can basically 1v9.

Dont even want to Talk about towers... They were actually weak as hell, everybody complaining about It, and riot nerfs them Even more XDDDDD I died, Someone explain me.