I wouldn't argue with the factual aspects of your assessment and honestly, I never really saw the appeal. It definitely appeals to brits where class and family are still a thing. My paternal ancestors come from there and while we have one of the first crests registered with the college of Heralds I rarely have any reason to mention that.
As for the retelling part, well, yeah. What's your point. There are very few truly "new" plotlines. All stories involve conflict or romance. It's no accident that the Assyrians had the same goddess for both love and war (Ishtar). That's why I love scifi and some fantasy. It adds elements that you don't find in history or classical stories like the Greek and Roman myths, legends of Arthur and Charlemagne, etc. But as for classic tropes, they just keep getting recycled. Progeny recapitulates ontogeny.
My wording wasn't the best. I cannot id any story Harry Potter retells, if any. My point elements of the world are clearly based on real U.K society.
I do find Harry Potter rather impressive in that while it is evidently based on real society with subtle shades at the elements of society(or particular individuals that irked her), it is distant enough and the individuals are relatable enough that you are indeed in a different world with its own logic and charm. People feel for Harry and his perspective. The literal story is good. But there is also social commentary that manages to be present but not intrude the literal story.
It is evident Rowling has very little regard for the official "government" or the Prime Ministers, represented as the Ministry of Magic. Fudge turned into a sour one quiet fast. Pius is clearly a puppet and a shade against the Catholic Church. The use of Dementors is a point that even the conventional states we are familiar with are willing to use a powerful, terrifying force to enforce compliance.
The Houses in Hogwarts are actually three groups of elites and one inclusive one. Slytherin is the nobles by blood. Gryffindor are the blessed folks who destined to earn a "SIr" or "Dame", and Ravenclaw is the intellgientsia, such as the Oxford and Cambridge educated. The Asians happen to be in Ravenclaw.
The Dark Arts could represent all those "vice activities" and secret little transgressions the higher ups engage in but get away with due to their power. The likes of Epstein shows just how they just get away with it.
Sirius' rebellion on the familial level is easily understood. But it also may refer to a hidden message where younger nobles broke ranks with the parents beliefs.
Arthur Weasley is a good guy, helps the protagonist, but even his character has a little shade. He too still is of a noble lineage, he sympathizes with the outsiders(Muggles), but has no comprehension of their world.
Ron too, has an overall good guy demeanor, but in thd matter of house-elf freedom, he is stuck in his world's paradigm of dominance oppressed when it came that particular group. Hermione though, became a bit woke and sort of a white knight for their freedom.
Cricket is the basis for Quidditich, but reading of Quidditch matches have very good visual and sensual imagery.
Harry is very much a trust fund baby of sorts with many blessings that comes from the sky, but the reader always sympathizes with his suffering and growing pains in his life. One of the not-so-obvious messages is that the battle between him and Voldemort is a battle between the
I would say that the perception between non-U.K and U.K individuals might be quite different. U.K natives would find it "familiar", but outsiders are pulled into new place that are enchanted by predominantly the characters and literal story.