We've not hit this point overnight - it's been decades in the making. But I'm not sure we'll ever 'fix' this by small incremental reforms around the edges. We need some moonshot revolution, but I'm not sure we have enough collective appetite for that.
I'm not saying that the current system in the US is great, but moving to a 100% "single-payer" model will not get rid of claim review.
With the ever increasing ageing population, and stagnating economy, the pressure on the healthcare system balloons while the money pot is finite, so the existing resources keep getting split more and more aggressively creating a system of winners and losers. It's inevitable when the resources are finite but the demand virtually infinite.