About Debuffs

No, this is not a thread crying about nerfs XP. More, it is something that i have noticed over the course of this game's life span.

Basically, i've noticed that champion abilities that apply "Debuffs" on the opponent have been kinda disappearing. Not talking about CC here btw, but abilities that make your opponent fight worse, like reducing their stats. And every time a champion that has these abilities gets reworked or just returned, they tend to lose them, Like when and Lost their ability to reduce enemy attack speed and just recently lost his damage amplification ability (granted it only affected him). The only champions that still have abilities like this are older champions who still haven't been reworked, and who still can reduce armor.

As someone who loves to play as characters who make the enemy fight worse in all games, i find this bit of a shame. But is there any reason for this? Were they broken?