Two simple things i'd like for ranked MM next year.

1. Duoing adjusted. Removal or restrictions to MMR not Tiers. This is exclusive to Solo/duo que.
2. Players do not receive a Tier or division with out achieving a statistically significant # of games into a que. Personally id like it to be the average # expected for system accuracy... So when your K factor is done lowering. but if riot wanted to just do it as something arbitrary like 100 games that would work also. Players just overvalue tiers over anything else and ignorance on MMR systems is gonna consistently generate that mindset.

Pretty simple imo.

Complex things would be the return to a 5man Team ELO system with Clan/Guild mechanics replacing Flex que that ties into Clash and seasonal Events ultimately that promotes the very best grassroot team into pro games.