I think its preferable that the government establishes the floor for working conditions and firms compete for workers with added compensation.
One thing that I suspect distinguishes my position from more rightwards critics of unions is that I believe in robust cash transfers, for example I believe we should have a fully refundable Child Tax Credit(CTC) with no earned income threshold and ditto for the Child and Dependent Caregiver Credit(CDCC)
The idea being that instead of allowing specific constituents to engage in rent-seeking through mechanisms like unions you offer broad redistribution in the hopes that it strengthens the bargaining position of workers generally who then compete in the free market for jobs. More specifically, redistributing income through cash transfers like CTC and CDCC reduces poverty rates among parents and other caretakers of dependents who are disproportionately poor due to having to commit to the unpaid labor of caretaking.
In a perfect world the government would take care of that which then gives workers more flexibility to switch jobs and not worry about losing coverage.
The social contract I'm envisioning here is based on free markets, robust public goods, and income redistribution. You get stuff like education, healthcare, and public transit paid by the government as well as some cash, from there you figure it out on your own. Rent-seeking by actors like unions and landlords should be discouraged.