Why Arm. Pen Builds are so Popular

So we all know that the armor pen build is becoming standard on the more meta adc's and they are working on changing it. But it has also affected other champions as well such as . The reason:

1. I think players realized that crit is to unreliable, there is to much RNG for the impact it has on a match. Of course when you don't crit it increases the chance that you will next time, but that one time you don't may decide a fight/game. Especially on adc's, who wants RNG to decide fights because the enemy crit more than you. And most of the ADC's that build crit build it because their kits provide a steriod for having putting money into crit, such as Both buy crit items because their passives provide a boost to non-crit damage so they aren't loosing as much when they don't crit. ( Yes I know ashe always crits on frost shot enemies)

2. The game has shifted into a more mid-game focused matches, and sense crit takes awhile to stack up and is expensive it primarily used for late game damage. So how do you fix the mid-game, you build armor pen/shred items early to nullify some of the armor the enemy is buying. This effectively increases your damage earlier than crit and can carry over until you get some crit. So armor pen. is like a psuedo crit steriod, providing more damage to auto-attacks and abilities earlier with a smaller power bump instead of just auto-attacks and a few abilties later with bigger damage with crit. That small power bump can cause champs to snowball over early and mid-game and become hard carries late.

So as it's been stated before and I'm pretty sure Riot has said that they may intend to rework it, the CRIT system needs to be redone somehow to make it more reliable. I don't really have any ideas how to do this, but if it becomes a healthier mechanic we could see more adc's in meta and maybe some different builds every once in awhile.