whats the point of mr and armor if im getting fucking one shot anyways???

Gives everything but raw AD burst and raw HP a reason to exist. Other wise it would be a very simple game, everything else is just counters producing a ton of fluff.

I laned against kayle as tahm and even if I built thronmail, frozen heart, dead man, ninja tabi and adaptive helm she would still destroy me

At this point, tank stats are just a noob trap.