Champs made for other game modes instead of SumRift?

I was just thinking... Theres alot of champs in league of legends... some are barely ever played on the rift because either they are to weak or just... yeah usually they just fail in comparison to other more popular or stronger champs... l noticed riot has a hard time balancing some of these champs and its understandable the game is extremely complex. So sometimes brokeness tends to happen... or champs being bad tends to happen...

anyways the main thought of this was... what if riot made some unpopular Summoner rift champs and made them better or changed their kits to better suit other game modes? just a thought i feel like it would be a nice little change for people who dont play on the rift or just wanna play their favorite champs in a game mode where they are pretty good....