> Electric cars are supposed to be simple.

The only part an EV doesn't have is the engine and gearbox. Admittedly, these are pretty major components, but it's a technology mature enough to be extremely reliable if the manufacturer cares to make it so.

But what an EV has instead is a massive battery, charging electronics, a DC-DC converter keeping the 12V battery charged, and various electric motors and actuators for the air conditioning and coolant loops. These are significant more reliable than oily engines in lab environments, but the automotive environment tests the mettle of seemingly resilient components.