What is wrong with the ranked system

This isn't a rage type post. But what the hell is wrong with the ranked system? I find it impossible to play a game not have some troll or afker. I am bronze, yes. But it still isn't fair to lose a game and lp because of it. I put time into this game only to find out someone going to troll. Then I lose, get mad, a don't want to play your game anymore. In my opinion, riot should spend more time banning these people instead of toxic players, you can't control toxic people but you can control trollers. I try hard to win, get out of bronze, and hopefully climb. But how is that possible with people from the left and right are just plain down dumb. Without a team you can't win. This is a team game not a solo game. So please spend more time banning these people.

Thank you