Private health insurance -- as Americans have come to expect it (and demand it) -- is unsustainable on its face ... for all the reasons you cited in your post. Everyone wants to have access to unlimited financial resources to pay for any and all medical procedures they may need in their lifetime, but nobody really wants to pay the cost of it. So "health care" becomes nothing more than a shell game where people pay the cost of what they demand without realizing they ARE paying it.
Private health insurance is like Marxism. It's built on a business model that has no basis in economic or physical reality, so it eventually collapses under its own weight.
Bingo - amazing how many people don’t realize that. Private healthcare insurance is not insurance. Disaster coverage for healthcare would be real insurance.