Ehh, but fundamentally its just 1-2 motors and a big battery.
No alternator, fuel injection, radiator fluid, oil, pistons, spark plugs, fuel pumps, exhaust, manifolds, shafts, rods, gears, blowers, turbos/superchargers, catalytic converters, etc.
Not saying it's easy as described with unstable lithium chemistry, and its own heat dissapation problems, but MECHANICALLY it is fundamentally simple.