Elazar ben Ya'ir, the commander of Masada during the Roman siege, made a colossal choice. When you stand there at the western ramparts you ask yourself, "How could they let the Romans complete the attack ramp? Why not just pummel them with rocks and arrows and fire and stop the construction?" The answer comes from the chronicles of Yosef ben Matityahu (Josephus): Elazar saw the Romans were using Jewish slaves to build the ramp and he decided not to kill fellow Jews knowing full well that he will pay for this with his own life as well as everyone on Masada.
When all options were exhausted Elazar ben Yair was among the 10 men chosen to kill everyone on Masada in a prearranged suicide pact refusing to fall captive. So he was forced to kill not only fellow Jews but his closest friends and family among them. You can judge this decision and this act according to your knowledge or according to your values, but you can never say: "What did he accomplish at the end? Would it not be far better to just prevent the ramp from construction and save Masada?"
There is no way that Flavius Silva, the Roman commander of the siege, would ever let the Jews escape from Masada unharmed. In the end they would be captured, killed, tortured, enslaved and women and children would be violated - it was well known as all this happened two years before in Jerusalem when Romans destroyed the Temple. Above all, the Masada Jews would be killers of fellow Jews (the ramp workers), for a fraction-chance of saving their own lives, which would be in reality no chance ultimately. Rome sent almost HALF OF THE ENTIRE ROMAN ARMY to put down the Great Jewish Revolt. Half of giant imperial army for the tiny Judea...
Masada kana'im had no chance. But within a "no chance" situation, they chose the most honorable end after the most impressive resistance.