It is NOT clear this is true for the first 10,20 or 50K miles though, and that's about as long as a rental company owns the car, so attributing financial gains from EV vs. ICE seems spurious at best.
If you own a large fleet of vehicles, and especially with the way people treat cars that aren't theirs, some non-trivial percentage of those cars are going to need service that goes beyond mere fluid replacement, even within the first few ten thousand miles. This may not apply to the modal rental car, but it will apply to some of them, enough to bring the average up non-trivially.