Weighted LP losses, their should be a system that grants higher lp losses for a higher amount of deaths as well as less lp losses for someone with a lower amount of deaths.
ie, i should not be losing the same amount of lp for playing my role perfectly as compared to my mid yasuo who's 1/10 and has clearly given up trying. Banning these players, doesn't work. I'm toxic af and i literally could not care less about your honor system or being banned, HOWEVER, i do care about climbing, i want to be the best shaco in na.
therefore if a system rewarded me for playing to the best of my ability by making my lp loss lighter when i get THAT team, i will be less likely to become frustrated and rage because i know the system will still reward me in some capacity for playing my best and that the player going full na first timing a champion in my high diamond game will be punished by dropping elo quicker.
(also the system should detect how often the enemy jg is in your lane and take that into account cause sometimes it is just unfortunate to get the hashinshin treatment but this is just a rough idea i came up with whilst taking a shower)