I can tell you right here and now why Hogwarts don’t use pencils and instead use freaking quills (the worst writing implement I’ve ever held in my hand) and it’s all because of this British school bullroar called “brand image”
The reason we have uniform, out side of trying to avoid class privelage, is that we use our students as human billboards advertising our schools.
But schools don’t just sell an image. They also sell a mythology. Schools put loads of effort into cultivating a history for themselves. You end up with things like photos of trees framed on the wall. Trees! Sometimes as students you’re collectively required to do things which make no sense. I remember in primary school the ENTIRE school had to learn and perform an entire song and dance, and then perform it, in front of nobody. But that event can then be part of the school mythology and used to sell the brand image.
Hogwarts is a school of witcraft and wizardry. And God damn it, the teachers will force you to LARP as witches and wizards to the maximum if it will reinforce their brand image and make sure wizarding families dont start getting thoughts about Durmstrang.