School uniforms were designed not only for institutional recognition, but also for social equalising. When school clothing becomes a fashion parade, I imagine that concentration on classroom work fades.
I've just found the above photo of my own alma mater, a tad before my time; and looking decidedly like something out of 'Goodbye Mr Chips'. I see mortarboards, short jackets, and stiff collars; more like my father's school uniform. These days gowns of various ilks are worn, and in my day we wore boaters; which I rather liked.
The school clothing department of a well-known Knightsbridge shop, from whence our uniforms were purchased, was always an 'interesting' place. I remember lots of dreadful mothers overseeing the purchase of ill fitting jackets for their little Cedrics or Poppets (they were bought to 'grow into'). Time there was best kept to an absolute minimum.
I wonder how much longer rigorously strict school uniforms will last. I suspect not that much.