Licensing is merely a subset of the larger credentialing world. Even in your doctor example, the license is not the issue - board certification of a specialty would be the issue.
How?
"Licensing has nothing to do with your credentials past having them."
The way that most credentialing is used for employment.
Not all credentials are licenses, but all licenses are credentials.
You can look up some definitions if you want. I'm done with this conversation as you are so set on arguing a tangent without an open mind.
License: a permit from an authority to own or use something, do a particular thing, or carry on a trade
Credential: a qualification, achievement, personal quality, or aspect of a person's background, typically when used to indicate that they are suitable for something.
Sure, you can characterize the license as an achievement. But it's really just a license.
Maybe, maybe not, but its 100% a qualification, so its definitely a credential.