Clearly you've never had shitty insurance and a need for a doctor. I've spent multiple hours on the phone trying to find someone that takes my insurance. It's an actual problem.
Go to the insurance company web site.
Several years ago a law was passed requiring insurance companies to keep their provider lists accurate and up-to-date.
There's a regulatory window for freshness, and every insurance company web site is required by law to show you when the data was last updated.
It’s already often difficult to get a human on the phone.