School uniforms on girls look sexy (High school) or cute (Before high school). Guys all look like they are in a military school. I prefer to let them all dress how they want.
Uniforms cut down on the cost of teen clothes and it hurts the market. Let them wear what they want. Girls can be plain or sexy if they want. Guys can be neat or sloppy. Let them be them. Not clones.
But Japanese girls in school uniforms ... hubba hubba.