@Meddler, is there a reason there have been no champs with 2 or more on hit abilities like WW ult?

I've been playing for 3 years now, and as far as I recall, the only champs that had really good on hit abilities were pre rework Fiora and WW. Their ult gave 5 on hit procs. Over those 3 years, I've never seen a champ with more than 1 on hit ability.

I ask this because I really thought Camille would be the one to have a 2 or 3 on hit ability. I also thought riot was linking hybrid champs with on hit abilities.

Is Riot avoiding this in new champs and slowly removing it out of the game with reworks? If so, why?