Unpopular Opinion: Bans on ARAM are gone for good, just unlock all champs
There's nothing wrong in having some OP champs on ARAM since by the nature of the game mode itself you know that by the random draft you can end up in heavily favoured matches depending on the picks that everyone got.
But, Riot should make it so all champs are unlocked on ARAM for all accounts, this would kill the infamous arams accounts and would also make it so the players that for their playstyle on Summoners Rift have bought lets say all mages adcs and supps dont have an advantage over the players that for their Summoners Rift playstyle own all the Tanks and Juggernauts.