Let's see the average school uniform is rather unisex except for the boy's trousers replaced with Stalin looking jumpers for girls and ladies golf skirts. Both have an unisex assortment of bland color polo golf shirts and a sparse selection of button down shirts, usually white and blue. So if a parent has to spend their limited clothing allowance on these types of clothing for their child to attend school what is a young lady to wear on a date, a dance, a picnic if her parents need not purchase two sets of clothing? Should she opt for the Stalin jumper and maybe accessorize with a red star pin or the old lady golf skirt? According to you advocates for school uniforms, there is no other clothing requirements for the parents and that is obviously not true. But if the student was permitted to wear what their parents end up having to buy them to wear outside of school, of course it would be less expensive.
Without the additional cost of uniforms, for a family with 2-3 kids, just getting all the haircuts, eye exams/glasses updated, shoes and additional items needed for sporting activities, physicals, dental appointments and the ever growing list of supplies each pupil is to provide along with all the tissues, hand sanitizers, toilet paper. Cripe a kid can't make it to class the first day carrying all the crap they are told to supply. Enough!