I'm the same age as Sarah, and my school was not far from Sarah's. We had a prom at the end of year 11 and year 13. No they weren't as big a thing as they are now, dress code was more general going out clothes so there was no pressure to buy new and there was a meal and a disco. I didn't go to either because I didn't want to, but that was my choice so I've never felt I missed out. Maybe Isabelle wouldn't have wanted to go, but what about Esme? She really wouldn't want to shop for it, film tik toks of getting ready with friends if she had some?
All they have done is take away any options for the children. No one has to have qualifications but it's a lot easier to get it out of the way and then not really need it than realise in their 20s that they really do and have to spend time working at it or proving they have the relevant skills without it - which they don't. No one has to go to prom, or go out with friends, or attend extra curricular activities but it's better to have that choice and maybe try some things before deciding it's not for them.
At school I was very academic and hated all the subjects like PE, Drama, Music, Art. I would have happily done without them and spent all my time doing Maths. However, I know for sure I don't like them because I tried. I'm absolutely useless at them, but I had the opportunity which led to me being sure that wasn't the path for me so I didn't choose to take them any longer than I had to. They do none of that, other than some craft time for Jace and Mila which is usually done at home with toddlers anyway.