Scrap MMR, add performance based LP gains/loss
First of all, shit would be a lot more transparent if we removed the MMR system and directly put people in the rank they belong in instead of having them play against them from a different rank.
Second, a big incentive to force people into continuing playing until the game is over would be to add performance based LP gains/loss, or MMR if you must keep that system. This would also give less power to trolls as they would fuck their own rating harder than they do others' when they purposely do bad or give up. A person with an S does not deserve to lose the same amount of LP as the person with a C+ or B, this would allow for people to get to their deserved rank a lot quicker. It would basically just lessen the variable of teammates on your own ranking. Obv for this to work you would need to perfect your rating system and not allow people to get an S solely for good farm.
It does not need to be a massive difference based on rating, but it would definitely feel a lot better than everyone gaining/losing the EXACT same LP based only on their MMR.
I'd like to hear any arguments against these suggestions, as I believe it would heavily reduce toxicity in this game. I'm toxic myself and I would 100% try harder in most games if I knew I'm tanking my rating harder for not trying in a game that is probably a loss.