Arcade Mode?

Howdy I'm new to the forums so pardon me if this has been discussed before. What do y'all think of an Arcade Mode similar to Overwatch? We could have the Rotating Game Mode there along with Twisted Treeline, ARAM, and maybe some other neat game modes that Riot could make permanent.

We could have cosmetic rewards limited to the Arcade, and we could have a weekly amount of games won that would reward players with something (like a chest or a champ shard). I think it would help keep the player base active during slumps of competitive play. I know I get burned out and just wanna casually enjoy League.

While I understand that Riot doesn't have much time to tune every champ for every game mode, I think this would be a good reason to expand the RGM dev team and thus expand casual and fun LoL experience.