Why did riot make conqueror such a strong rune than nerf its best users?

Lets give an example of 3 champions with best synergy with conq

Jax

Irelia

Yasuo

Both jax and irelia were nerfed. Yasuo became A/S- tier from being just a bad champion overall. What all of them have in common is high sustained dmg + high attackspeed. Now the 20% true dmg part of conqueror is fine and does its job, but problem with conqueror is how much AD it gives when it procs. its 6 − 35, that makes it give you 20AD at level 9. Which is insane on champions that have attack speed but don't build alot of dmg early on, like yasuo,irelia,jax....

For example 20AD at level 9 gives jax 70-80(depending on E charge) dmg to his instant Q-AA-W-E combo, which gets even crazier the longer you fight, and that is ignoring true dmg conversion it gives.

Yasuo is probably the best conqueror user. It honestly makes his S- straight from B tier. Because he builds berserker's + PD, which is 0AD and just AD from conq is enough to deal reasonable dmg.

What i'm saying is, conqueror shouldn't be straight no brainer choice on every champion, it should be a tool that allows bruisers to fight with tanks, but AD it gives just makes it strongest rune whoever you are fighting. Even master yi became a champion that is not a troll pick, mainly because of this rune.

If you look at rune stats post game, you will see that conqueror usually does at least as much dmg as PTA/comet/elect/dark harvest if not more in longer games. But that dmg doesn't count the bonus dmg you did because of AD it gave.

I just think its overtuned and that champions shouldn't really rely on a single rune to make them viable, instead nerf conq and buff champions that used it the most.