They use square waves for them because squares are much easier to make, not because they work better. Good driver chips (e.g. https://www.trinamic.com/ https:/

They use square waves for them because squares are much easier to make, not because they work better. Good driver chips (e.g. https://www.trinamic.com/ https://www.trinamic.com/) still synthesize sinusoidal-like waves for these motors. It reduces noise and power consumption.