I recently took my daughter in for a medical checkup. The practitioner ordered a scan and some labs. They directed us to the providers associated with their campus. I called to verify that they take our insurance. Nope. So
I had to find out who does, call her provider back, and have them fax over orders. Of course there were glitches in the process, and it took extra phone calls.
It occurred to me that besides likely costing less, because we wouldn't all have to pay a profit to the insurance companies, a benefit of a single-payer health care system would be simplification. No going through the rigmarole of who coordinates with the insurance you have. And repeat it the following year when you get a different insurance company. Quite frankly, I have more confidence in our government than in most of our endless-profit-driven corporations. The government is not perfect, but there are checks and balances.