It's funny because you're basically making the argument that it's not solely the insurance providers fault, but also equally the providers (which is what most reputable studies on why American health care is so expensive seems to point to).

If a hospital doesn't know what it's own costs are, and are doing creative accounting to hide charges in random places, how the hell is an insurance company supposed to know how much reimbursement makes sense, and if a procedure should be done that costs $10K at this hospital vs $5K at another down the street with seemingly no difference in outcomes.

So w/ the creative accounting, which both the provider and the insurance company knows everyone is doing, you get administrative bloat where both sides have massive billing departments dedicated to figuring out each others BS. And this bloat is a hilariously large amount of the reason why costs balloon.

Both the providers and insurance companies are aligned in driving up costs. Hospitals probably will never get their act together in knowing actual pricing, but lying about it through creative accounting hurts everyone.