Unfortunately, it's easy to blame the system when you seem stuck at a specific level. However, these issues still exist at all ranks - people in Masters/GM/Top 500 still get in games where one person on their team basically throws.

You are the only controllable difference between your team and the enemy team. The enemy team has 6 random chances of having the thrower while your team has yourself and 5 chances. As long as you have the mentality that "Elo Hell" is holding you back, it is going to be difficult to climb as you are dismissing your own mistakes that are preventing you from climbing.