I used to work at a small company that manufactured medical equipment. One of the products we made was a pick-and place robot that handled urine samples.

It needed a coordinated 3-axis motor servo motor control, which we initially planned to use PLCs for, however after looking around and seeing the price tag of the stuff that matched our required feature set, we decided to build our own. We were up and running within 2 months, and I can tell you, writing code in C for the control loops is infinitely preferable to whatever monstrosity PLCs can be programmed in. I'd say this is a much more complex scenario than running a single motor at a certain speed depending on some sensor readings.