You say I missed the entire point but your very next sentence is automatically wrong.
They are not both fighters. Neither of them are even fighters. Yasuo is a skirmisher. Fizz is an assassin.
Yasuo WW works autonomously to protect everyone behind it. For Fizz to get the slow, he has to E and NOT use the E2 jump and then just drop down. There is both time to move out of the way or the ability to just punish and/or kill him now because E was his only safety tool and he used it for a melee range slow instead of escaping now.
Zhonya's is an additional item factor with 120s cooldown or so. That is irrelevant. No, not all point and clicks can h dodged with his E. Technically, he will just prevent or disable the cast altogether before it starts which stops it from going on cooldown, for applicable abilities like Darius' ultimate for example.
Fizz's E mobility is clearly obvious. If he Es twice, he loses the slow and it's basically just a somewhat long dash that is clearly obvious which direction he's going. The only exception would be if he's right next to a thin wall. If he Es only once, then he drops into the middle of the enemy team and dies.
Q is situational and requires an enemy team and can be both dodged and interrupted due to the way it works.
Fizz's PT is not "stronger" than WW. You are comparing apples and oranges and trying to defend one being better. I'm saying your point is invalid because it's based off an incorrect assumption in the first place. They are not comparable abilities. They serve completely different purposes on completely different champions with completely different playstyles.