> In contrast, the internal combustion engine on a 172 makes enough heat to keep the cabin warm whenever needed

Right, and it's always making that heat whether you need it or not. So it's a good thing your avgas has a shit-tonne more energy density than my batteries because you're going to need it to waste all that heat.

Look, physics is physics, you can't cheat it. Which means pure electric is only good for short air trips (energy density), but there's plenty of room to make airplanes more efficient (internal combustion = waste machines).

So those who are busy saying it's impossible should get out of the way of those who are doing it.