A large part of my career as a lawyer has been devoted to navigating these differences in federal, state and local law which you discuss. I advocate whichever position which will help my client (unions and workers) at the moment. So I have successfully argued that federal labor law does not preempt state remedies for collecting wages, while federal labor law does indeed preempt claims by employers against unions. This includes the state-local dichotomy you discuss. For example, we lost the battle to uphold state prevailing wage law in California, the courts finding it to be a matter of "local concern" which certain localities can opt out of.
While arguing these federal-state-local conflicts pays my bills, I'm not so sure I would embrace your proposal as a matter of policy. (Just as I would personally like to see my union health fund clients put permanently out of business by single-payer health insurance).
The problem with our society is that it is so shattered into self-enclosed groups, who don't talk (or listen) to each other. Although we have the technical tools to connect people (the internet - what my father called the "Mass Information Utility"), it has been programmed to encase us in smaller and smaller bubbles of like-minded people.
I don't know what the answer it, but I don't think it is making our political structure as balkanized as our social structure.
Somehow, we need to reach out and talk - and more important, listen - to each other.