It's not meant to be a well sewn up world building project. It's literally two different worlds smashed together on a bunch of napkin notes. None of us read it for its intricate political maneuvering or realistic magic system.
And that's why I bailed around book 5. Around that point I decided I wanted more realism, so I switched to Tom Clancy and JRR Tolkien, and I have been reading more "realistic" fiction ever since.
You brought up a really good example of a fantasy world with boundaries by mentionning Tolkien. It is heavily insinuated in the LOTR books that "magic" is not "endless posibilities magic", it has more to do with special aptitudes and/or knowledge depending on the race (like elves or wizards). It's not like Gandalf can just snap a finger and transform someone into a chicken. I know it limits what you can do with your world but in the case of HP it opens the door to endless plot holes and contradictions.
An author’s ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the reader understands said magic.
It works for HP because it's targeting kids, but adults get frustrated because Rowling just makes up stuff each book. For example, why are port keys not a thing before book 4? (it would be a lot easier to take a portkey to Hogwarts than a train) Because they're a plot device at the end of book 4, and almost never used again.
Rowling uses magic way too much to solve problems in HP and she does so inconsistently, but that's totally fine because the point of the story is to appeal to kids and inspire imagination (and kids love quick solutions to problems), not to appeal to adults.
Really interesting concept you brought up, did not know that law and yes it makes perfect sense.
And I totally get your point, but it is still an issue to me considering that she wanted to keep the audience hooked as they aged. As someone put it in another comment, in the first book, Harry is eleven, it appeals to kids ~11 y.o, and so on. But, and I speak personnaly, by the fifth book it was already too disjointed for 15 y.o. me. Her books are like a Jojo's Bizarre Adventure book/episode, but without all the corny humor and the self-awarness that makes it fun.
Idk, my oldest kid is 10 and has finished the whole series. She may have intended kids to grow with the series, and that was certainly true when they came out (I remember my cousin reading the books as they came out), but I do think they have limited appeal to more mature audiences.
That said, I do still read YA novels, and I'm definitely not the audience, so I'm sure there are plenty of older kids and adults who aren't as bothered by plot holes and whatnot.
If you like realism in a fantasy setting, Delicious in Dungeon absolutely delivers. They take world building to a whole new level of detail.
It's a bit light on the high level stuff like global politics and history. But for an example of the level of detail they went for (keeping it vague to avoid spoiling anything), one problem they solve involves a character knowing how dragons are able to breathe fire. Even though they have magic in this world, they still came up with a plausible physical mechanism for how dragons breathe fire and wove it into the plot.
At another point, a character gives advice about best practices if you're about to turn into stone.
I do appreciate realism, but I think I care more that magic (or technology) use is proportional to its impact on the plot. For example, I love hard-scifi stories, but only where the details truly matter for the plot (e.g. The Moon is a Harsh Mistress) and not as much where it distracts from the plot. I also don't mind totally unrealistic settings, provided the magic/tech isn't needed to drive the plot (e.g. The Wheel of Time 1&2 is more concerned with character development than how the magic actually works).
It's hard to gauge where this one would fall in that regard tbh. The plot is written around the level of detail and kinda even feels secondary, like it's just there to give them a goal to work towards while the show itself is about a party navigating their decision to just cook and eat monsters they defeat in the dungeon instead of buying rations.
The only thing I don't like about Delicious in Dungeon is that there's not enough cooking. Maybe Senshi could teach us about preserving food in various ways - pickling, brining, salting, smoking, maybe even canning - in future episodes.
Even better if it happens accidentally due to some monster just being a monster around some food they initially think is ruined but then realize was just changed.