This will probably help a bit but in an emergency people don't have the time to compare prices. And with US health care, it just takes one accident that sends you to the ER and where someone that's out of network performed a procedure to end up with a bill that's tens or hundreds of thousands of dollars.
https://congressionaldish.com/cd227-coronabus-health-care/
“Starting on January 1, 2022, any health insurance company that provides “any benefits” in an emergency department can not require pre-authorization of those services or deny coverage because the emergency department is out of their network. If emergency services are provided out-of-network, there can not be any limits on coverage any more restrictive than what would be covered by an in-network emergency department and the out-of-pocket costs can’t be more than they would be in-network. Out-of-pocket payments at an out-of-network emergency room must count towards in-network deductibles and out-of-pocket maximums.”