I found the updated 80s books very perplexing. I knew they were children from the 30s-50s, so why were they in jeans?
I had just come from reading E Nesbit and Noel Streatfeild too, so I had a good understanding of what children wore, quite well calibrated, at every point from about 1880 onwards. It was obvious to me by age 10 that children at different periods wore sets of things that I had never worn - but I was very clear on what they were.
In books of Enid Blyton's era they had slacks, tunics, rubber-soled shoes, galoshes, mackintoshes, knickers with elastic and pockets (where you could keep a Ten Pound Note at Malory Towers if you were a spoilt rich girl). Boys in shirts with collars, boys only wearing shorts not trousers until they were about 16.
Just as Victorian children wore long drawers, the mysterious "combinations", liberty bodices, petticoats with lace on Sundays, flannel petticoats at other times (good for stopping trains with) frocks, aprons over them, Sunday suits and general smart clothes made of velvet on Sundays, lace collars. Button boots, socks with garters. They had an endless war against smuts on their faces. I didn't know what smuts were.
And in the 30s little girls also had tarletan frocks with frills on for dancing in and shiny dance shoes with white ankle socks. No idea what tarletan is. School uniform included felt hats with hat bands in school colours and sailor hats in summer. Little boys wore hard wearing tweed suits with shorts, shirts and ties and school caps. Everyone always had handkerchiefs all the time. All boys carried a penknife and all girls carried a pencil stub.
Clothes had to be made and cared for differently too, and I understood that until the 50s frills might be whipped, collars could be starched, frocks might be basted, darts might be put in things, hems might be let down (if velvet, this didn't work as the underneath velvet would be newer-looking and create a line, which was a shame). Until long after the 50s socks, jackets and other clothes would certainly be darned and patched and otherwise reinforced. Doing Mending was a thing, it could take up your time, was often expected of girls, sometimes you would even have to mend sheets and pillow cases, and the job included large baskets. I stress I had never, myself, done any of the above things or even seen them done!!
I have really enjoyed remembering all this and writing it here. I am sad to think that the rich cultural and social historical knowledge I imbibed PURELY from children's books might now be erased by bowlderising and updating.
With children reading less and less, even if books are not updated they will also have less exposure to these kinds of exciting yet confusing descriptions of clothes, food, homes and so on, that you had to puzzle out, from reading many books set in each era.
It's not the same to get a general impression of Holmes and Watson on screen with clothes and accessories, as it is to read "His stout Malacca cane" and try and imagine what the hell it looks like, its colour texture and purpose.