Would the game be better if spells were capable of crits?

I am legit asking this because I have never understood why AD can have critical strikes and in the case of gain full crit chance off one item when critical strike in ANY other game is supposed to be a rare thing that builds up slowly. Why can we not have critical spells and critical heals but they happen a lot less often, it would feel ultra rewarding if you landed a spell and it did MR penetrating true damage like Conqueror does at the moment.

Why do only AD champions get these super satisfying plays.

I do say that any crit spell stuff should be kept as far away from as her awful design is pretty much the sole reason that AP champions cannot have good items at the moment.