Much of this has to do with your perspective about what qualifies as fiction and what is important. We watched
The Tudors where every line of dialog was made up, so the only standard is does it support the historical record? Sadly on many occasions it did not, so entertaining but fictional.
No hard feelings on my part, it would be nice if you could concede my point

, yet…I’ll live if you don’t.

The people who crated this show based it on the life of Queen Elizabeth. It would not do to make up a false history or it would be called complete rubbish. For The Crown, you can say oh this was fiction or can you? It depends on what level you hold the show to. It can be said that Prince Phillip cheated on Elizabeth on his world tour, and she reacted to it in a certain way, and you can also say those conversations did not happen in that manner but it did happen and then dismiss it all as fiction, but that would be a mistake Imo.
I’d counter argue the show did not make this up. Princess Diana’s history because she spoke out about her experiences is likely the best documented, and it is your option to describe it as a work of fiction, but at it’s core imo this is truth at a fundamental level. Charles did pursue her under false pretenses, there was a knowledge within the monarchy that Diane was being deceived, and that for just about all of their history together until their divorce, despite the Crown’s efforts to keep Charles in line, he was unfaithful to Diana. Sure, call that fiction, but I choose not to without further qualification.
This article supports the idea of a historical drama but not a documentary:
"There are two sorts of truth. There's historical truth and then there's the larger truth about the past," says the show's historical consultant, Robert Lacey.
www.townandcountrymag.com