Some doctors claim that during the first wave ventilators were used too much and too early (instead of just breathing masks). Ventilator can actually damage your lungs. At the same time, cortison treatments were banned, another decision several doctors criticised (including a relative of mine). During the next waves cortison treatments and a reduced use of ventilators decreased the mortality rate a lot.

Doctors didn't dare to go against the guidelines, even with their reservation (they could be held responsible if they did).

Some people I know wrote a book on the subject and are claiming we should held governments accountable for those dead in the first wave (and they've been promptly censored and facebook-banned out of existence). I tend to err on the side of incompetence more than malice.

That said, there is plenty of ignorant people claiming ventilators kill based on statistics - but it's usually the other way round: once you need a ventilator you're either dead 100% or you can get a 40% survival rate with a ventilator.