Bonsoir, that is an interesting comment. From what I have seen in the US, uniforms including tie and blazer and smart khaki pants tend to crop up in all-boy schools set up to be non-failing alternatives to state schools. They are also used in areas where gang activity makes the clothes and headgear you wear a significant choice. Also in elementary schools where academic achievement has been poor and discipline a challenge.
The more middle class and motivated a student body and the safer the neighbourhood the more you are likely to find the schools have no uniform and maybe a very basic code (no nudity, no see-through clothes, no swimsuits, no head covering in school, no body parts from collarbone to start of legs displayed through cutouts, no flip flops, no offensive slogans or symbols displayed on clothing - offensive under categories such as racism, sexism, ethnic or religious intolerance).
Nooka -- my mum sent us to the school she chose (having given up on the local National School that had no uniform due to massive overcrowding) based on the uniform, which she thought very distinguished. Looking back, a red v-neck sweater and red tie might not have been the best choice for a primary school in Ireland, where so many children have red hair and pink/freckled faces. The uniform continued to secondary but the tie was dropped. Ties in primary had to be tied, no elastic allowed. I learned this life skill (so important to women the world over) at age 5.
What I really needed was lessons in how to apply makeup but makeup was completely verboten, as were high heels, and funny enough those two elements featured prominently in my list of things that caused me angst as a young woman in the world of work. My uniform and the regulations on appearance prepared me for life as a nun. Worse, being forced to accept the constant comments on appearance from teachers, nuns, etc., went a long way towards conditioning me as a girl to accept that other people had a right to comment, judge, remark upon and correct your appearance. It's quite a boundary infraction.
I noticed even in the DCs' primary school (a school with good points too numerous to list) that when it came to field trips to a play or an opera when the DCs were supposed to wear their own choice of clothes, the policing of what the girls wore was far more in evidence than policing of what the boys wore. One teacher in particular was downright neurotic about clothing and notorious for calling mothers on field trip days (never fathers) and insisting they bring something 'more appropriate' for their DD. She sent out a list of banned clothing styles and footwear, with a drawing of what was considered acceptable. It was laughable. The kind of outfit she wanted girls to wear was basically the uniform, but in different colours. Most mothers told her where to get off, that they were at work just as she was.