I don't understand the arguments that private health care is better because of competition. What competition? I can't comparison shop for health insurance, if I

I don't understand the arguments that private health care is better because of competition. What competition? I can't comparison shop for health insurance, if I don't use what my employer chooses I have to pay thousands of dollars more in premiums for an even worse plan. And then I am limited in the providers available by the network. Not to mention that comparing prices is impossible when you don't know the price until months after you receive the service.