Here is the Jane The Actuary decree on titles: if you are in Germany and have a doctorate, you have grounds for expecting to be referred to by "Dr." in everyday life. In the US, you should expect to be given that title only in the context of academia, e.g., by students or ---

colleagues, or, in the larger media, in the context of your role as a professor or a researcher, if applicable. Outside of these contexts, the usual titles of Mr./Ms./Mrs. are just as appropriate for you as for the rest of us.

And, yes, this is in reference to the WSJ commentary, though it didn't make its pitch clearly enough. https://www.wsj.com/articles/is-there-a-doctor-in-the-white-house-not-if-you-need-an-m-d-11607727380?reflink=desktopwebshare_twitter (Plus, I'm really not a fan of handing out a "doctorate" without a dissertation.)

So, yes, if Ms. Biden were to present a paper at a scholarly conference, and the news media were to report on this, it would be appropriate in this context to write, "Dr. Biden's research showed that . . . " but it is not appropriate to write, next year, "First Lady Dr. Biden ---

unveiled the White House Christmas decorations and spoke to children about the importance of working hard in school." The End.

Oh, and one last comment: the US appears to be out of step with the rest of the world in claiming these sorts of degrees to be "doctorates" at all, per Wikipedia. https://en.wikipedia.org/wiki/Doctorate#Professional_doctorate.