Wins and losses are no longer adequate for determining MMR
Some sort of rating system has been needed for years now. It would be really cool if someone at Riot put literally any effort into improving the clusterfuck we have right now, where the majority of games feel like dice rolls.
It's frustrating to consistently perform well and still barely hold 50% win rate, because there's little to no reward for playing well; the worst player influences the outcome magnitudes more than the best player(s), because no matter how good you are, you can't win the numbers game when the enemy team is thousands of gold ahead.