It's the cost of batteries! What else can you buy now for a tenth what it cost ten years ago?
Pay for a dozen eggs, eat two and compost the rest? Duh!
Problem is you just can't make it much better. The thermodynamics, the physics, just won't let you turn any more of that gasoline flame into motion. Even in the most ideal theoretical engine, the one of engineers' fiction, 2/3 of the heat is just waste. Like every other kind of waste, something nasty you have to try to get rid of.
The EV doesn't waste nearly as much. It's much closer to eating ten and trashing two.
Imagine this conversation. "Hey Kids. Brought home some doughnuts. We have to throw some away. Maybe feed 10 the neighbor's dog...or just 2. What you think?"