When did this 3 hit proc thing become so overused by Riot?

I saw another thread post something about this and it made me think about the champs who have this mechanic. For the longest time, the only champion who had a 3 hit proc sort of skill was Jax. But then,

Xin Zhao was made and then Vayne was made and then Diana was made

after this it was fine, because that was only like 3 champions out of 95 or so? But then

Vi was made and then Aatrox was made and then Gnar was made and then Ekko was made

Can you stop reusing this mechanic? You guys were fine for awhile but like after Vi 1/4 of the last 16 or 17 champions have some "you hit 3 times, now here's some extra damage and maybe some other effect" skill.

I know you can be more creative, I'm just worried that this is going to be some overused trend in every new kit