Those are details, incremental changes. ICE engines still have a transmission and drive train that is for all intents the same as it was 100 years ago. Yes, everything's more refined, but it works the way it did then. ICE engines are either air or water cooled, that hasn't changed.
They are incremental changes, true.
The transmission is nothing like the transmissions of 100 years ago! Even the drive train has changed completely!
Gone is the old manual transmission with no sync rings. Today, the modern transmission is BELT driven much of the time, or at least an automatic. Yes, a slight resurgence in manual transmissions is making a comeback, but they now have modern sync rings, making them MUCH easier to shift, and fluid or electric clutches, eliminating that friction component completely. No more clutch pads to wear out!
The drive shafts are less common now, favoring front wheel drive cars, using a solid shaft instead of a long hollow one.
Even the brakes have changed a lot. Fewer and fewer drum brakes even exist on cars, favoring the far simpler disc brakes.
EVs use liquid cooling for their batteries and motors. Without that, instant fire.
Gasoline engines also typically use liquid cooling. The coolant is pretty damn good, too. You don't have to change or flush the system every year anymore.
Cooling has changed a lot.
EVs also have a transmission, although it's a fixed transmission, making it simpler. Like any transmission, it is also liquid cooled.
Not having a carburetor or distributor or high tension ignition system is not merely a detail. It's a completely different way of handling the engine. About the only that's similar is the piston and the cylinder (although improved materials now make them last longer and perform better), and spark or glow plug (depending on the type of engine).
Even the gaskets have changed a LOT. 100 years ago, it was considered routine maintenance to replace your head gasket every few years. Today, with the new materials and more precise design, these gaskets often last the life of the car (assuming you are not abusing them).
About the only other thing gasoline cars have from 100 years ago is a gas tank and exhaust system, and they are also both now made of improved materials.
Sure, there's useless shit on gasoline cars, such as the catalytic converter, which effectively does nothing significant. I call them pollution to pollution converters. They are only there because they are required by the government, and they are expensive, being made of platinum, palladium, or rhodium (all currently worth more than gold).
Pistons, rods, cranks, and transmissions have been around a long time, and are found on more than just gasoline or diesel cars. You find them in external combustion engines (such as steam engines), internal combustion engines, air compressors, certain types of fire extinguishers, syringes, water wheels, air conditioning equipment, EVs, water supply and sewage treatment systems, etc.
Yes...EVs have pistons. You'll find them on the brakes and shocks.