UAW would rather have half the employees but with the same, over-inflated pay and benefits, rather than keep everyone working and lose a single dime in benefits or pay. THe union sees any loss of pay or benefits as a defeat and an insult to those hard-won labor agreements. It's pride over practicallity.
They're killing the golden goose.
Company I worked for killed their most productive plant, their most profitable plant, their highest quality plant and the lowest accident plant all to save plants where they had invested $$$. I then went to work for another company that did the same thing. All the deliverables management asks from employees and they still were closed.