That's exactly what the left wants, but they are facing bipartisan opposition from both Republicans and the majorty of centrist Democracts, both of whom receive large donations from the massive insurance industry that stands to lose everything.

Giving it to everyone is the cost reduction.

Leaving aside the question of old age and focusing on healthcare for people of working age, it is almost always cheaper to intervene earlier, and it helps people get back to work sooner. The case is even stronger in children where healthcare gets to determine if they get to live a decent life or not.

Not to mention the benefits of time saved fighting back and forth over bills.

A little bit of cost control pushing people onto the cheaper versions of insulin and things like that, in the manner of the UK National Institute for Clinical Excellence would help. This is also what every private insurer does, but people go bananas when contemplating the idea that the government might do it.

Oh, and pharma marketing needs reining in. Some of the people who were marketing opiates should be jailed for the damage they've done.

Medicare has for a long time been banned from negotiating drug prices in most instances, and that is a large part of the problem. They have a limited indirect ability by basically being able to contract with private healthcare plans to provide services, who in turn can negotiate, but it does in no way allow them to leverage their size to the full extent.

Compare to e.g. the UK where the NHS does not just negotiate on generics, but also use the considerable value of their contracts for generics or drugs that can easily be substituted to drive down prices on other drugs by bargaining on combined contract values.