Hmm what are they servicing on an EV that ends up cumulatively costing only £10 less than a comparable ICE? No oil change, no transmission maintenance, so just consumables like filters (no engine air or oil filter on an EV), brakes (brakes last much longer on most EV's due to regenerative braking), wiper blades, cabin air filter, rotate and balance the tires?In some cases probably yes. In this case a main dealer service is £10 cheaper for that EV and there are no tolls/parking/city charges cheaper for EVs within 100 miles.
The first EV I purchased was a BMW I-4, the dealer tried to sell me the extended maintenance package which was not discounted from the ICE version of the BMW 4 series, he couldn't justify why.
The other point beyond maintenance is just repairs. 10 years the EV battery will have been off warranty for two years (typically 8 years 100,000 miles). The engine and transmission on the ICE will likely have been out of warranty for a long time (typically 5 years 60,000 miles).