At one time, it was harder and more expensive. You could do open loop stepper control with four big transistors, some logic, and a whopping heat sink. Closed loop meant learning how to tune the loop, and also involved the cost of the encoders.

If you're using surplus parts, then getting enough documentation to make a servo system work can be touch and go. Steppers are pretty much brain dead simple.

Even with servos, the entire machine has to be pretty stout in order to ride through a bump that would cause a large stepping motor to miss a step. At that point, if it's a homemade machine, something else will end up out of kilter too, such as your clamping or the workpiece itself.