I was in the playground with DS (9, year 4) and some of his classmates were also there, of the 6 children, 4 of them had smart phones - definitely their own phones rather than parents (who weren't present) and they were watching tiktok and showing each other things on Instagram. We had parents evening later that day and the teacher said over half the class have a smart phone in school with them. At 9! I was genuinely shocked.
AIBU to be shocked.
At year 4 the school doesn't allow them to walk home alone.