They have lux, they have fizz... so let's not build MR at all. Lux and Fizz are insane damage-output AP champs. I'm starting to doubt it was your team that threw the match.
And Tgump is right. Pros don't win 100% or even 80% of their matches, even in Bronze, but if you are good enough at leading a team, statistics will help you climb your way out. And it's not that the pros have insane skill. Not even the best pro can 1v5 an enemy team. After 30 games in ranked, I began to realize that I have the skills to climb out of bronze, but I didn't have the mindset. Instead of just depending on myself, I took the time to become a team leader. My winrate isn't immediately 100%, but it's improved from barely 50% to about 65-70% winrate. Coordination and objectives win matches, not someone who carried a team with a score of 500 and 0.