I agree that car accessories like radios, seat belts, and CD players have improved significantly, but that does not translate to ICEs themselves being significantly improved.
Combustion engines:
1923 - 14 mpg
1966 - 13.5 mpg
1991 - 16 mpg
2019 - 25mpg
Electric cars:
2009 - 85 mpge
2019 - 113
Drivetrains, fuel efficiency, sustainable fuel (solar panels built into the body of the car), battery tech improvement, and so on.
Electric cars have all of the accessory improvements you’re talking about related to ICEs, but are also rapidly minimizing all the relevant material, environmental, and even maintenance costs of manufacturing and operating vehicles to become more sustainable at a much more rapid pace than ICEs have.
Those numbers will go down once everyone is driving 4wd EV Suburbans with half-inch steel plate armor (you know, just so they feel their kids are safe) :)