Not to dismiss your point, but the US healthcare system has one meta problem.

Complexity.

There are too many parties. There are too many bespoke party-party contract. There are too many new middle-parties being created, with their own contracts. There are too many systems. There's too much tech debt.

That's a reason improvements to the US healthcare system have generally been via HHS/CMS imposing standardization mandates ('or no Medicare payments').

But providers, facilities, and insurers (most operating on low margins) can't be collectively more meta-efficient without simplifying the system.

Single payer / Medicare for all is a critical start not because of coverage, but because of simplicity.

There are so many intractable problems with the current system simply by virtue that changing anything about them requires 100s of parties to update 10,000s of party-party contracts and interfaces.

That's the biggest source of waste in the current system: constant duplicative re-engineering.