Should you also have the right to work at the company and not be forced to contribute to shareholder profits? Surely any management that was actually good for workers would have no reason to oppose such a measure.

I'm not asking to be in the union but not pay the dues. I'm asking to not be in the union.

I’m not asking to be considered a profit contributor but not contribute to profits. I’m asking to not be a profit contributor.

Isn't that just not being an employee? And no company can not let you quit.

No, I want to be an employee. I simply don't want to be forced to join the shareholder profit contributors group, as that would be an attack on liberty, free association, and voluntarism.

"If cooperation is actually the better choice in the prisoner's dilemma, why do you care if I defect?"

What prisoners' dilemma? What part of collective bargaining agreements give benefits to employees who choose not to join the union?

All sorts of benefits bleed over to non-union employees. In fact, unions have had an upward effect on wages and benefits for management in many corporations that I've worked at. Along with upward effects on wages within society overall.