Jax is only strong because his counterplay (mages/tanks) may as well just not exist anymore
Try playing a mage mid in solo que. I dare you. Play Vel'Koz mid and see how much fun you have playing against Zed/Katarina/Leblanc/Fizz/Ekko/Yasuo/Akali/any other assassin EVERY SINGLE GAME.
Jax's counterplay is disengage or cc. What isn't in the game anymore thanks to assassins overshadowing every single other class? Disengage and CC.
Jax isn't too strong, his counters are too weak.
muH wEaK mAgES