It seems to me that champions that got hurt the most in preseason are the one-dimensional ones

Compare and .

can use almost any item in game, and the same applies to keystones. Right now he abuses Aery, because it's the shit for champions with range advantage on their enemies, but if the strongest keystone was in precision or domination tree, he would easily switch to that one.

only is only really good at one thing (which is walking up to people and rekting them). More so, like 90% of his players, except for the most diehard mains, follow the same build in almost every game . The chance that nothing in the new rune system would support his playstyle strongly enough was much, much higher.

Of course, some one-dimensional champions got lucky, too, like , but in general the chance for that was just much lower.