The internal combustion engine is fantastically cheap for what it entails. It's as complicated as a bloody rocket engine, but an entire vehicle can be bought for a few months California rent. It took literally trillions to engineer it to what we have today. Companies don't want to abandon that investment.
And yet... That's what they'll have to do. The electric car will be so much cheaper to make (and is so much cheaper to operate and maintain) due to its fundamental simplicity that as soon as battery costs get lower, nearly everyone will be forced to transition to electric.