Crit should work on a fixed number of aa.
We all know that dodge was removed from the game because it relied on luck and not skill. So it is hard to understand how crit is still a thing in this game when it relied in complete luck . You can make a great engage against someone with 8% crit chance and the chances are that they could totally destroy you because it happened they got 3 or 4 crits in a row. Unlikely, but perfectly possible. That is no skill and that is no fun. Crits should work over a certain number of aa. Lets say one good crit item makes your 9th and 10th aa of every 10 aa to crit. While a weak crit item makes 1. And if you are full build crit you could get a 100% crit chance of 10/10 aa. This would definitely works towards skill and decisions. Just like Aatrox W you have to decide how you are going to use the 3rd attack. Having crit early game on the 10th attack of 10, would also make you work and think towards that 10th attack and how are you going to reach it. This could also create counterplay. If your enemy just used his crit attack on you, you can know, looking at their items, how long they are going to be without it.