My two cents on critical strike chance.

I'm not that experienced, so it basically IS two cents, but I just like theorycrafting.

Critical strike chance is, in a vacuum, a % increase to your auto-attack DPS. 30% critical chance means that ideally over 10 attacks, 3 of them will deal 200% damage. Meaning that, over those 10 attacks, your total damage went from 1000% to 1300%. Critical strike using a pseudo-RNG as it does in League reinforces this, but pseudo-RNG is still RNG, especially when it comes to the chances of something that ISN'T your consistent auto DPS critically striking.

Also, the RNG nature of critical strikes causes them to functionally give sudden instances of burst damage to a class that's supposed to be based around DPS.

So why not cut out the RNG entirely while also making the damage actually scale with the game instead of just being at full blast from the start? We have another stat that curbs early power by scaling its effectiveness with time, that being Lethality, so maybe a modified critical system could use it as a base?

Brawler's Gloves

Cost: 400

+10 Precision (placeholder name)

This "Precision" stat increases the AD ratio on your champion's basic attack by a portion of the listed value that scales with your Level, the same way Lethality functions. On the in-game stat display, it would replace critical strike chance with your champion's current basic attack ratio.

Infinity Edge would maintain its current function, increasing your Precision by 50%.

Essence Reaver's mana restore passive can be modified to "Your basic attacks restore 0.02% of your Maximum Mana for each point of Precision you have." Of course, the in-game tooltip would just display the percentage restore you currently have, which with just Reaver's 20 would give 0.6% max mana back per AA. This restore is slightly weaker than live ER in a vacuum, but returns to equal value if built alongside IE, which is a concession I kinda had to make due to this stat working differently.

Also, if this sort of change were to happen, turret armor would have to start and scale higher/faster than it does since, unlike critical strikes, this would affect turrets. This would solidify one of the actual reasons for picking an ADC, though, that being to have a scaling damage source that can chew down turrets in the mid to late game.

/-/-/

Of course, then a new problem arises. Now you have champions like Ashe, Jhin, and Yasuo, who have different critical scalings than the norm and who would need to be changed, in addition to champions like Yi and Garen who have abilities that can critically strike for an irregular amount of bonus damage.

It sounds like an easy fix, but it's really not. So many things being designed around a pseudo-RNG stat has created a tangled mess of balance problems.