The impact 1 player has on your team...
When 4 roles are winning the game on your team, and your top laner decides to run it down mid after typing "thanks for nothing jg"
When the enemy team is so greedy for LP that they don't report him and instead praise his toxic behavior in chat
When you feel like quitting league because toxic players are everywhere and ruin the game and make you lose your hard earned LP
But you're addicted. So keep playing!