In my lifetime, when I went to see a GP he had one office assistant, almost always a woman. She wore a white uniform and many thought she was a nurse, but she was an office assistant. She made appointments, took in cash, did some bookkeeping, and was present when a male Dr. examined a woman. The Dr. paid her salary.
Today the same Dr. will have 2 or 3 assistants, a couple of insurance billing specialists, and a full time bookkeeper. The Dr. pays their salaries. Now the insurance companies have 3 or 4 people on staff to reject the bills from the Dr. unless they are exactly correct, and a supervisor for them.
So, today we have 10 straphangers for every Dr. and someone must pay their salaries.
It doesn’t have to be that way...
How you describe how it used to be in the US is how, for the most part it is in places like Mexico and Panama. That’s the main reason the costs are so much lower (like they used to be in the US)