I have a similar original Medicare and supp plan, no co-pays or bills and I pay a lot for it.
However, in my area, DC Metro, many docs have opted out of Medicare and make no bones about it. They won't take you on as patient unless you pay out of pocket.
There are many boutique practices and many excellent physicians are leaving medicine.
The area is horrendously over-populated and there are not enough docs to go around. Add that to the standard 10-15 minute appt they allow themselves to be with you and the concern for excellent care is not possible.
Wherever you are, glad you're getting great care and happy with your Medicare.