I don't think eliminating private insurers is a panacea. I just think that the nature of incentives and negotiation between hospitals and insurers has resulted in plainly ridiculous chargemaster prices that harm uninsured and underinsured patients (including those who are "out of network").

Public disclosure and reputational price-indexing as well as regulation of emergency and regionally-monopolized non-elective care would help a lot, but backing the train up on decades of broken incentives and profit-optimized behavior is no small task.