Medical facilities are forced to artificially inflate bills. Insurance then artificially gets a discount back to a sane price. This helps insurance look like they're "doing something" even when they aren't e.g. High Deductible when you pay 100% up to the deductible ("at least I got the insurance rate!").
Out of network also suffers from this. The networks themselves are discount networks and prices for uncovered patients are artificially high.
If you banned insurance discounts and insurance had to pay the same dollar to dollar cash price (without kickbacks/incentives), it would help the uninsured, it would help re-align patient/insurer motivations (i.e. both demanding low cash prices), it would make price transparency actually meaningful, and it would eliminate insurance networks.
But ideas like this, and removing employer provided healthcare (e.g. everyone on an open health insurance exchange) are politically impossible in the US because no politician can get elected for "taking people's employer insurance and taking their discounts." Even if they're the right thing to do to simplify, reduce costs, align goals, and force insurers to compete again.