>When I was a teenager in the 90s I had a classmate tell me he "can't be friends with me because I don't have Nikes".

Wow that is an insane level of pretentiousness. Probably dodged a bullet there.

>Its one of the reasons some countries have school uniforms

Most schools do have uniforms here, honestly it doesn't really matter that much, teenagers (can and will) find another way to show off.