Motor oil for internal combustion engines doesn't last very long because it needs to work in a very large temperature and pressure ranges, from a cold start in winter temperatures to the high operating temperatures of an engine with a bunch of little explosions.

The oil is also directly exposed to the combustion chamber so it needs to be able to be filtered for whatever contaminants come from combustion, and it needs to not combust itself in that environment.

The oil also does double duty of being a fluid that takes heat away from the engine, and can exchange heat with the radiator fluid in order to cool the engine of excess heat.

All that together means that we ask so much more of lubricants for ICE engines than for the other moving parts in a car. An EV will have lubricants that aren't exposed to the same operating conditions, and can last longer without needing to be replaced. Basically they're more like traditional transmission fluid than like traditional motor oil.

I mean, yeah, there's oil in there because there usually is still a transmission that has two gears (forward and reverse), so obviously there have to be gears and those obviously need lubrication. However, as there is nothing burned it usually really is just for lubrication and doesn't really accumulate dirt or deteriorates in other ways. In fact I just checked and both my cars have no transmission oil changes in their maintenance schedule because it just doesn't need to be replaced. Like, ever.

Yeah, but I don't need to replace that regularly.