"You missed the cause of all of this: no nationalized healthcare. A single-buyer can negotiate prices"
Completely wrong, both in your analysis and causal claim.
Reduction in tool failure means human failure will be statistically more common. That does not mean human failure has increased nor does it mean aggregate failure has increased. The "rise" of human failure, all things being equal, is GOOD NEWS. It means tools and methods are far more reliable.
To illustrate: Human failure is far more likely an issue of injury in a vehicle incident now than 40 years ago. Fatality rates are dramatically lower while human cause has increased.
Competition lowers price and increases quality.
It is a system in which success ultimately requires being more productive than your competition.
Monopoly is incentive to do as little as possible while demanding as much as possible.
Competition encourages altruism.
Monopoly encourages extortion.
"Single payer" requires the impossible condition of maximum efficiency and altruism from the most inherently selfish and lazy structure possible.