All cars, regardless of fuel, are extremely flammable. Once they get going they burn quick & hot. The fire department usually doesn't spend much time trying to put out a car fire inside a garage, they knock it down enough to throw a chain on it and drag it out onto the driveway.
> the insurers don't, care about the car catching fire
Of course they do. You think an insurance company would cover a vehicle using an open flame for power at the same rate and an ICE? And how often do charges actually catch fire where it’s not a total loss? For the insurance companies, the result is the same - a replacement.
I can tell you that insurance companies charge more (though low double digits on the year) when your house is heated with e.g. a pellet stove vs a typical oil furnace.