US courts defamation of of public persons is extremely hard to sue over.
That used to be true. The difference is that the statements being attacked as defamatory are far more outrageous than the kind of thing over which public figures previously would sue. The result is a lot more successful lawsuits by public figures than we used to see a couple of decades ago.
I haven't heard a cogent reason why, except possibly international judge shopping considering the Biden's have bragged they own the legal system there.
Also, Owens contends that she responded to the Macrons demands in writing, offering them ample opportunity to refute the allegations made and they chose not to, which takes the malice component of the suit off the table.
Finally, Owens work is derived from an investigative book written by French author Xavier Poussard and published in France. Macron has not sued that person in a French court which begs the question, why?

How is this defamation? There is nothing more noble to the Left than a transvestite.
Indeed.