Why does everybody look like in the 90ths

I was a few years abroad, but now I live in the City I was born ( at the center of Europe/ 4 million people).
and something changed. I know that art and fashion is more something for big cities, but why is everybody looking like in the 90ths? Technobitches and Guys with glittery and unicorn-shirts/tattoos, haircuts like monks??? Oh my what just happend?
--> I am in my late 20ths. So the the Style looks very old-fashioned and sometimes embarrassing/ homelesspeoplestyle...
Is it a phenomenon, which happens around the world?
French/ American/ Australian / say something...