I think the worst parts of the ACA were the parts that were essentially sops to private-sector interest groups, i.e. an individual mandate without a public option (a sop to insurers) and the continued inability of the government to negotiate drug prices with manufacturers (a sop to Big Pharma). Reforming those aspects would greatly improve individuals' market power, but something tells me you'd be more concerned with the loss of freedom on the part of the business interests involved. So you could see the most sensible reforms as "doubling down" or you could see them as fixing inefficient and inequitable corporate welfare.
So Medicare is in need of "reform," as you say, but your position is that we're better off with the status quo ante. Same thing with the ACA. Good luck selling that to America.
There's no way a program like Medicare or Medicaid would have ever passed in the age of Social Media.