in my country you usually participate in costs for the ambulance, and it's not cheap.
To be honest for an emergency situation (bleeding out, back injuries) the ambulance is better since it's a very medicalized car with a doctor (sometimes the doctor is in an accompanying car).
It's not like the ambulance in some other countries which is less medicalized, this also makes it more expensive of course, so there are some medical taxi services that take over some roles.
In more isolated areas, there are emergency posts with an ambulance-in-waiting, so the time is not so critical, and if it's really in the boonies they'll just send the helicopter.
I am insured for the helicopter as I go hiking, and the same organization also provides medical repatriation via ambulance jet so it's a no-brainer for anyone who travels to poorer countries. I am not insured for the ambulance, but I haven't needed it yet and it's cheaper to just pay the 2k I have to pay if it happens, maybe once in my life. The helicopter bill is much more expensive if they decide you can afford it.