I got a book thrown at me in middle school by a teacher who thought I was lying that I'd finished the whole textbook when he told me to try working ahead if I was bored.

When I handed him a stack of all the end of chapter tests to prove it we had to schedule a meeting with the principal to figure out what I should do next. It involved having to go to another school in the morning because mine didn't have anything else to teach me, and I can't help but think you're right that enrichment would have been a better solution for everybody than that was!