Champions MS enhancers vs slows

This game might as well be called the 3hit league of slows with the sheer amount of slows that are tacked on to just about everyone's kit because its a relatively safe mechanic that gives sometimes hidden, sometimes not so hidden power to champions.

But this presents a problem!

With the sheer amount of slows in the game, why are champions who have no dashes, but have mobility spells like udyr's bear stance, sivirs ult, , blitzcrank W, Mundo ult, ect... not recieveing the same treatment as Garens Q? upon activation you remove all slows. It seems fair enough because its only upon activation that the slows are removed, so if you re apply the slow or its an AoE slow, it wont have much of an effect, but when used correctly it can help break the struggle of not having a dash/ having to use flash.