If you buy a piece of clothing now, you might see it on someone else when you walk down the street or you might not find it unique enough to buy it. But the fashion from the 90's is considered retro and cool. Sometimes, vintage is cheaper as well. Except if you go for an old Chanel bag, your chances of finding something really cool and cheaper than an H&M t-shirt are pretty high. You have to look around a lot though, it does not come in handy.
I love vintage clothing because I can get it for cheap, it is unique and I can change it.
For example, this past weekend, I bought a pink vintage t-shirt, very cheap and decided to add white bow buttons to bring in my "personal touch".