I hate to break it to you but very few vehicles are going to the dealer for engine/trans related work. Dealerships mostly only see vehicles that are new enough to be under warranty or recently out of it and major power-train stuff doesn't often break in that time period. It's stuff like steering and suspension wear items, the occasional window motor, trunk latches that won't pop, HVAC and stuff like that they make most of their money doing. EVs would probably actually net more money for dealers more money because they wouldn't take a loss on fixing random leaks under warranty (they get paid but book times are often unrealistic).