Why do people always use this goddamn fallacy?
CC counters every single champion in the game.
No, it does not counter every single one in the game equally well.
The ones you specifically listed are unintended abusive builds that remove their own weakness because of bad design of said tank items and then the champ's base damages/whatnot. Congratulations, you can cherrypick out what are essentially unintended bugs being abused. No, that does not magically make your point more correct.
People say specifically CC counters champions when they're talking about the squishy damage dealers.
Why? A tank doesn't give a flying shit if they get CC'd, they'll most likely survive it unless the entire enemy team focuses them. Which really shouldn't be happening if said tank engaged with their team. Also it's just bad decisionmaking to waste all the CC on the tank because then the damage dealers will murder you.
So what about said squishy damage dealer? If they get CC'd, almost none of them have any sort of escape mechanism. Coincidentally, like I said, they also have incredibly low health. Also coincidentally, they have next to no resistances if any at all beyond their bases/ones granted by runes/masteries/whatever.
So then what happens? Said squishy damage dealer proceeds to evaporate into nothingness over the next half second against any half-intelligent team/player.
Also, in regards to you trying to use another incorrect block of statements to further your fallacy...
If Ekko is CC'd, he would not be able to ult in the first place.
If Fizz manages to dodge it with Playful/Trickster, no, you did not CC him.
If Yasuo blocks said CC with his Windwall, you did not CC him.
Please actually bother making logical arguments before making a whiny thread like this.