That is not true on two fronts. First, doctors were not choosing who lives and who dies. They were deciding who would have the higher chance of survival if they were treated. There is no certainty that a) the selected treatment group would survive or b) the unselected would have survived but for the triage.
Secondly, that is exactly what triage is! People die, doctors are trained to decide of a group of people which are dying, who has the better chance of not dying.
I think this is missing the mark. Italian doctors were choosing who would get an ICU bed and who would not. There were more patients needing ICU beds than the beds available. Not giving an ICU bed to someone in need meant basically a death sentence. That is not the normal state of affairs, as far I can understand.
Well again, not _really_. We were also ventilating people who didn't need it. You don't need an ICU bed if you aren't vented. Furthermore, the mortality rate of being on an ventilator is non-negligible.
I would be interested in seeing if there is data to say whether being put in the ICU actually _increased_ risk of death. Of course this would be hard to prove as only the most sick went to the ICU etc.
Secondly, that is exactly what triage is! People die, doctors are trained to decide of a group of people which are dying, who has the better chance of not dying.