Even if I hated to wear uniform when I was in my high school, objectively speaking I think the advantages of wearing a school uniform outweigh the disadvantages.
Because by wearing a uniform, students can focus more on their study and avoid wasting time on trying to be special through dressing up. This will also reduce the behavior of comparison among classmates, which can protect those poor students' self-esteem.
The only bad thing I can think of is some people may think this will kill the creativity of students, because wearing what is also one way to show who you are.
I will support school to have a uniform if I was a parent someday.