For me it's a little bit around terminology on roles and encounter powers in effect being cooldowns.
Okay, but the thing to remember is, that terminology didn't actually come from MMOs.
It came from
soccer. There is no MMO that calls damage-dealing classes "strikers." That's a soccer term: people who
strike forward into the enemy part of the field in order to score a goal. No MMO calls support/healing characters "leaders." That's a soccer term: people who go
ahead of the strikers in order to set up a good shot for them.
I'm not sure if "Controller" is directly from soccer. That's the only one of the four roles that is, in fact, semi-commonly used to speak of stuff in MMOs...but it's almost never an actual
role, because a class purely centered around crowd control effects would not be very enjoyable. (Guild Wars 1 suffered this problem with its Mesmer class. It was an almost pure support/control class, having very little to contribute to survivability, healing, or defense, and only a very small amount of offense. This made it a great pick for your secondary profession, but they made a very difficult pick for your primary one. GW2 notably reworked Mesmer to have much more damage potential.)
I don't really see how encounter powers are "in effect" cooldowns. Like the only relationship is that you can't use them whenever you like. Such things have been in D&D for ages. I don't understand why "this trick can't be repeated over and over whenever you like" becomes a "cooldown"--especially because most video game cooldowns are
not once per fight, and much closer to once every 10-60 seconds, thus being "many times per fight, but not in rapid succession."
Consider, for example, the "rounds" of Rage or Bardic Music from 3.x. Those are far more
actually like MMO mechanics! Specifically, they'd be charged stances that rebuild charges when not active.
Cool downs aren't unique to MMOs either. Idk what game used them first.
Sure. But I'm not even sure they're unique to video games. For example, variable-recharge (e.g. roll a d6, recharges on a 6) might even date back to 0e, and that's functionally a cooldown with a slightly randomized duration (roughly, once every six rounds of combat, but you can assume it's always available at the start.)