A EV is a much simpler device than a ICE - it's a battery and an electric motor, it's much simpler than mechanical power. Gone are oil pumps, transmissions, etc.
On top of all this, you can now route power through electrical wires, rather than needing an accessory belt to distribute mechanical power to the A/C, oil pump, power steering etc.
The electric car's tech advances are mostly in the battery technology (and vapourware "Level 5 automation in 2019"). Tesla will have a unique differentiator in battery tech and production, but it's not crazy to retool an existing ICE manufacturer to EVs.