I don’t know how common knowledge it is, but private insurers bet the government that they could take the Medicare premium and offer better and more service than the government. The policies are called Medicare Advantage policies.
I have a “0”-premium Medicare Advantage plan, and I’m also elible for VA medical.
Needed cataract surgery. I could have it done at VA for free. The cost at a private ophthalmologist would total out to around $250.
I looked into it pretty carefully. The surgery at VA would almost surely be done by a resident as part of their training. The private ophthalmologist had done (literally) 10,000 procedures.
I went with the private doctor. Spectacular results.
This is another hidden disadvantage of these socialist systems.