I used to fly air-ambulance in Lear Jets. Some patients didn’t make it. You knew they were in bad shape when they were boarded. It was still very sad when one died but everyone was prepared for that possibility.
An air-ambulance is the right way to transport these very sick people. They have all the medical equipment.
Most airlines do not allow medical oxygen to be carried and for good reason. Some patients need to be on oxygen. Taking them up to a cabin altitude of 8,000 feet without oxygen will kill some of them.
Air-ambulances are equipped to transport these very sick people in a way that helps ensure they will survive the trip. Apart from the oxygen they are equipped with IV’s, monitors, real hospital style defibrillators, even “iron lung machines” to assist the patient’s breathing.
I won’t get into the blood born pathogens and the other health risks other than to say air-ambulances are equipped to handle them and an airliner full of holidaymakers is not.
We don’t put critically sick patients on a bus or a train to send them to the hospital. Why would anyone put one on a passenger flight? We have ambulances and air-ambulances that do the job and they do it much better.