Why is bronze rank so insane!?

I've only been playing for a few days now and my friend who's top 500 has been coaching me and spectating my gameplay, I'm consistently getting paired with bad teammates who either cannot tank at all or healers either not playing the right character. I've also noticed people who are far too good to be in bronze rank, like they legitimately have to be gold or plat players. My friend is telling me because they know the characters way too well. Long story short, how do I get out of bronze and break the cycle? I was in silver for a whopping 2 games.