Few elderly patients who end up on ventilators for COVID survive, plus the process is very painful and causes permanent damage if you survive. So morphine actually sounds like a pretty good way to go, assuming there's some form of informed consent.
The problem was that there were cases were consent was not given and of healthy 70 year olds having to fight for ventilators at least in the beginning. From what I understood a lot changed when people realized what was happening in June 2020, the paper is pretty vague about this it talks mainly about the first half of 2020.