Nine out of every 10 Medicare recipients have supplemental or Medigap insurance. Do you have that? Medicare Parts B and D are now a means tested, four tier system depending on income.
As well intended as Medicare may be, it is unsustainable financially. We can't afford it as currently structured.
Then what remains is [a] reduce the cost of medical care so that it is self-sustaining or [b] have more private insurance coverage, if affordable, to cover inflation and new developments, or [c] rely on family or charity.
I'd keep the present system until a new one is created for comparison. I regard it like fire insurance where all homeowners pay but only the one whose house burns down, collects.