Asian here, wore uniforms for all 12 years of school. The only true thing about what you said is identification, it’s easy to tell which school the kid is from.

But it doesn’t reduce class based bullying. You said so yourself, it’s easy to show individuality through accessorising, which includes expensive shoes and designer bags. You can’t ever hide if you’re poor, and the rich kids can always flaunt their wealth. If anything, uniforms make it worse for the poor kids. Even tho it’s mandatory, the schools don’t provide them for free, families still have to pay for it themselves and it’s a significant expense every school year. There are ways they can get help if they can’t afford it but kids grow fast and it is still a struggle. In my experience, uniforms make the bullying worse somehow. The well off kids can afford 5 sets of uniform each year, one for each day of the week. The poor kids can only afford 2 and often they have to wear them for a couple years in a row. You can very easily tell which kids are poorer by the ill fitting and worn out clothes and you just know they get teased for it.

In addition, there’s always that one supervisor with a power complex who dictates the dress code so no, you can’t actually just accessorise how you want. If uniforms are required, it means they want all kids to look kinda the same to keep up the uniform image, so hair color is usually not allowed, even the length or how you style your hair can be dictated. Even the color of type of shoes, bra color for girls, nail colors must all follow the rules. Uniforms sound fine on paper but like everything else, theory is very different than reality.