The vast majority of crewmate losses are attributable to one factor: the third imposter. Usually someone who accuses a crewmate of venting or killing who was actually innocent. So they always get at least two people voted off including themselves since people assume the person who accused an innocent person of being imposter must be imposter themselves. But sometimes these people are right, and you end up getting the imposters off the ship really early even though they didn't do what people accused them of doing.
Recently, I was questioning someone why they accused me of venting when they weren't imposter either, and another crewmate responded with "lying is part of the game." I never considered why you would lie as a crewmate before. When they're crewmate, third imposters are named such because they don't care if they're on the same side as you or not. If they have a suspicion of who the Imposter is, but no proof, they'll make up proof. This almost always either wins the game for crew if they're right, or loses it for them if their hunch is wrong. The third imposter behaves the way they do not to troll people, not because they don't understand how the game works, but because their ego is so large that they literally cannot conceive that their initial suspicions could possibly be wrong, and the few times they are correct cement that behavior.