Historians are written by genetic material as well as experiences and reactions to both.

History is

And historians work for the victors.

Anne Frank wasn't a historian.

"Just plain wrong" is not a proper response to "food is served hot"

You could argue that there is some history in the Bible, but a lot of it is not history at all.

I mean, you can functionally argue this with any book. Certainly, there are a great many people who take Biblical events as historical facts. And that's precisely because of the success of centuries of militant evangelism. Which takes us back to the whole "history written by the victors" thing. If nothing else, the Council of Nicaea - hosted by Constantine the I - was an explicitly recognized congregation of "winners". And they were very literally codifying the historical narrative of what would become the largest religion on earth for at least the next millennium.

Also, the Old Testament was written by the Jews while they were part of the Persian Empire

The Old Testament that we refer to in the modern Bible is but one version of the original manuscripts maintained by Jewish priests living in a minor kingdom at the far edge of the Persian Empire. It persisted in large part because Judaism gave way to Christianity, which became the state religion of the continent spanning Roman Empire. Had Constantine lost the civil war with Maxentus, there's no saying what the prevailing religion of the Mediterranean (and then the rest of the world) would have been. But I suspect we'd have seen at least a few notable variances to the modern incarnation of the faith.

Quotes from Chairman Mao

I don’t know what your second example is referring to.

Quotes from Chairman Mao, the very apotheosis of a victor writing history.

Seriously, how is that an example of history being written by the victors?

HP is a fantastic glamorization of elementary students growing up during the domestic fascist turn in the wake of WW2. It isn't simply a story about wizard kids, but an allegory describing liberals coming of age during the 60s and 70s. The heroes and villains and side-characters are all fictional re-imaginings of period figures. Had the English come out on the wrong side of the World Wars, you'd likely be reading a similar set of books translated off the German, telling a similar coming-of-age story about growing up in post-war globally dominant Germany as a young wizard coming of age with evil (((monsters))) hiding in the school basement that only a clever and talented Draco Malfoy could grow up to defeat.

History is not written by the victors. It is written by those who are most able to write history.

The folks most able to write history are the ones in the position to conduct research, formulate a narrative, and distribute it most aggressively. Those people are inevitably working on behalf of the most wealthy and influential business and political interests in the region. Aka "the victors".