The wizards had indoor plumbing starting in the 1700s. Most of the world didn’t have indoor plumbing until the 1800s. It would be hard to read the books and not know Hogwarts had plumbing. Your bad example notwithstanding, yes the wizards are ignorant of a few things that make no sense even though they use magic for every mundane thing, and it makes less sense since children would have to completely rely on their parents for any magical utility until they were pretty much grown. It doesn’t take away from the story, but if she did the worldbuilding like Tolkien, she probably would have noticed this and made small adjustments.
The wizards had indoor plumbing starting in the 1700s. Most of the world didn’t have indoor plumbing until the 1800s. It would be hard to read the books and not know Hogwarts had plumbing. Your bad example notwithstanding, yes the wizards are ignorant of a few things that make no sense even though they use magic for every mundane thing, and it makes less sense since children would have to completely rely on their parents for any magical utility until they were pretty much grown. It doesn’t take away from the story, but if she did the worldbuilding like Tolkien, she probably would have noticed this and made small adjustments.