The remaining fighters weren't stupid. They knew that if things continue like this then it would be hopeless for any of them to progress.
If they wanted to make a move they would have to target one of the three and that would inevitably mean that some of them would die but now it was not the time for hesitation.
At this point, the idea of dying was not enough to scare the people left in the arena.
Each one that had survived the bloody culling could be considered a ruthless individual in their own right and with their combat experience they would have inevitably spent many years outside fighting in sect missions.
They were the kind that would risk their lives for progress or the ones who saw this as their last chance to make it into the inner sect so we're either willing to succeed or die trying!
A bunch of reckless desperados!
Anybody that didn't have the resolve had already given up or had been killed directly