Why is Master Yi like that?

I just played a game...and i remembered that yi is a champ that has no logic behind him...like so much attack speed so much movement speed...and riot is not trying to fix it...the guy just kept his ult for like 30 secs because we got aced...30 secs of moving and attacking like crazy...also this champ requires no effort at all...i understand that he is one of the starter champs and he must not be complicated...but...dude...q that makes him untargetable and does dmg (it gets its cd lowered with every single auto attack...which is kinda broken even if yi has a bloodrazor) w that makes him take reduced dmg and heal...e that gives him true dmg in activation (he takes conqueror for extra true dmg) and an ulti that gives him attack speed and movement speed an each time he kills an enemy he gets ulti duration refunded...also...he does tons of dmg with his auto attacks...just needs to proc conqueror activate e there you go...200 true dmg with every auto...also 200 physical along with the true dmg and just buy guinsoo's and wits and get all three types of dmg in every auto attack...and from all this he gets insane attack speed...like wtf...yi with those items can melt a full tank mundo with ulti activated in 1 second...how is this balanced? Also the problem is not only with yi...there are so many champs that can deal so much dmg for no reason and can have so much sustain or even huge shields that last for too long (For example Nautilus)...there are champs that their roots/stuns/slows are ridiculous (For example Nasus/Morgana/Malphite)...or champs that can heal way to much in one ability (For example Renekton/Darius/Garen with his passive) and the strangest thing is that riot keeps buffing this kind of champs...For example, Malphite can oneshot an Ekko or Talon with an Ult --> Q --> E combo...actual oneshot...each ability deals 450-500 dmg...and this happens in 0.5-1 sec. Then darius got 2 or 3 buffs in a row...for what reason...his dmg was already too much...i once played against a Darius and he just turned a whole fight where i was 80-90% hp and he was 20-25% with a q...and he had just a phage...Garen is also one of "the starter champs" but...a black cleaver and he can't die...seriously...does more dmg with a black cleaver than a Yasuo with Statikk Shiv and I.E. I am seriously dissappointed in riot because they are buffing champs that don't actually need it and nerf champs that are soooooo neglected...Shen which was one of my favorite champs got a nerf on his q...for what reason??? his slow which was essential for his chases or 1v1s got nerfed. I seriously don't know where the RIOT Balance team sees the balance...but i don't how they can actually overpower champs for no reason and destroy other champs when they are neglected...there are so many things to be fixed and I don't believe it is that hard to see the flaws of the gameplay...I mean...they are obvious so they can't act like those flaws don't exist. I might be overreacting but i don't think i am not right about those things.