I build my own electric cars and a family friend asked me: Do electric cars still need a gearbox?

The question is excellent, because many people think you can just skip the transmission altogether and drive the wheels directly from the motor, but that is not the best solution. A gas car will have five gears, a big truck maybe even ten. This is to match the speed and torque as good as possible. Too little torque and you stall. To low a gear and you can't go fast. Even though electric motors have a lot more torque than petrol engines, it still makes sense to have a reduction gear with them.

The reversal: You could build a big petrol engine that does not need a transmission and has all the torque ready to get the car moving, but that would be expensive, wasteful and costly, you would end up with tractor like engines sticking out of the bonnet of your car.

Much better to pair a much "smaller" (can still be a V6 or v12) engine with a gearbox reduction. This is what every auto manufacturer does, no matter if electric or not. The simplification with EVs is that you only need one gear, so it is not operated by the user anymore.