The owner/operators at Nucor are doing just fine.
Nucor - I worked on a Nucor project during my days at SMS Concast (continuous casting machines). The package that the people at Nucor got was far more generous than the best union package. Add to that the workers (owner/operators) insisted on being cross trained since if a machine was down, that was lost production. So the operators were also trained on how to properly do repairs.
One other steel mills (Great Lakes Steel, Ecorse, MI) had a similar arrangement even though that was USW Local 88. In this case the tonnage bonus made up a big part of the compensation.