I'm sure you're right about increasing motor power being cheaper than adding gears, but just thought I'd add that my understanding is that you might then also n

I'm sure you're right about increasing motor power being cheaper than adding gears, but just thought I'd add that my understanding is that you might then also need to increase battery capacity because the rate at which Li-ion batteries can discharge is another limiting factor. As an example, I think there is a Honda 2 motor hybrid system which can accelerate faster (generate more power on the motor driving the wheels) if using power generated from the petrol engine as well as battery power.