It's been a little over two decades since I first attended university, but I recall that very few of the courses had a textbook. The lecturer wrote notes, be it

It's been a little over two decades since I first attended university, but I recall that very few of the courses had a textbook. The lecturer wrote notes, be it on paper to hand out or on the boards to be copied and annotated. Now and then a reference was made to a textbook for further reading or for some specific proof or some such, but in no way was any course taught from a textbook in such a way that you simply needed the textbook. This was at a university in London, reading Physics. I wonder how unusual (or not) that is? Is the heavy textbook emphasis a US thing, or is it more common? (About a decade later I read Maths with the Open University, which is basically the student on their own for six years learning some trick mathematics; a couple of those modules definitely taught from textbooks, although by no means all of them; some of them again simply provided notes and explanations and problem sheets generated by the university)