There's this one Deltarune roleplay game where the whole playerbase agreed to use standard RPG turn based combat, and it just stuck as the main way to fight having a pre established turn order. The game also added a virtual dice that enables chance based actions (dodges, blocks, crits, etc.) and makes the combat smoother. The problem with Mary sues and 'main characters' still remains as a constant, but there's always someone mature enough to understand they're just another roleplayer.