> surely even a rudimentary ventilator is better than no ventilator This is not a given. Ventilators damage alveoli, which (I am not a doctor, so not 100% sure

> surely even a rudimentary ventilator is better than no ventilator This is not a given. Ventilators damage alveoli, which (I am not a doctor, so not 100% sure) I think is not recoverable. Thus increasing air flow with a basic ventilator might do more harm than good, so whether it is worthwhile depends on the patient. That said, building good ventilators should be very easy as well with the modern industrial base.