What I mean by that is if I work for a large company, I can get access to health insurance that I cannot buy on the market myself. If that company changes insurers to a crappy one, my only choice is to change employers to one that provides access to a better insurer. If I self employ, I cannot get access to those plans.

Insurers should be forced to sell in a single market all the plans they offer. Insurer like to talk about "economy of scale" with large employers, but that is an artificial limit. Why should insurance pools be limited to who works at a company?