[fest]

I recall reading some hobbyist experiments that show that not all drivers implement microstepping equally: some have very bad angular linearity.

I can now find this article, but I think the one I remember reading also tested the torque in microstepping vs full step mode: https://hackaday.com/2016/08/29/how-accurate-is-microsteppin...

[jbay808]

Definitely, if your driver is bad there might be no improvement from microstepping, either.

[craftinator]

Bad microstepping timing in either the controller and the driver will definitely reduce torque.