For example, Hearthstone is a popular game. In it, it's considered trendy to add the last opponent to your friends list after losing a game, just to insult them. Especially if the opponent is also a "sore loser." Because of this, many people are hesitant to add friends after matches.
But, based on my experience, aggressive jerks who engage in such practices are a very small percentage. Approximately one in every 100-200 won games. They just stand out because you're not mentally prepared for the encounter.
Is this a "critical percentage"?
In my opinion, the same percentage exists in real life; gamers are no different. In real life, people simply mask their behavior because there, real consequences can occur. Gamers are even more peaceful because the main reason people retreat into virtual worlds is the desire to avoid dealing with the pressures and imperfections of the real world. Overall, the level of aggression here is actually lower. It's simply natural selection. Virtual worlds attract those who lack the aggression to fight in the real world.