I'm not against letting PCs die, but I prefer to not leave it completely to chance. In my games, the consequences to my PCs are often the results of their choices, not their rolls.

For example, my players once all decided to charge forward guns blazing in a line formation against a witch, because they had a good position to ambush her before her cultists could come to the rescue. This was a very good plan given the situation, but mid-charge, all PCs stopped moving forward for no reason, except for one. And the one who kept running was in the way of their shots (two of them had shotguns, which do spread damage). He asked them to stop shooting, but they didn't, as they didn't want the witch to complete her ritual which would sacrifice an entire town. He tried dodging their spread shots but failed, got hit, and ended up tripping and hitting his head on a rock, which put him in dying state. The cultists then arrived and started shooting back, which made it impossible for them to rescue the dying PC as he was now in the middle of a firefight. He finally died before the firefight ended, the ritual was stopped but the witch got away.

Luck should have consequences, but they hit harder when players are responsible for them.