[EthanHeilman]

Fashion can be used to signal many things: group membership, hobbies, political/philosophical views. Additionally, like other forms of art, it can also be used for intrinsic aesthetic expression.

The fashion industry like the luxury automobile industry or the art industry is based around selling status. Unfashionableness an industry release cycle designed around planned obsolesce.

[simplify]

Don't forget occupation. Doctors, police, prisoners, etc. all wear distinctive clothing.

[digi_owl]

Certain elements of the tech industry is heading that way as well...

[ghostbrainalpha]

Are you just referencing the iPhone? Or are there more examples?

[digi_owl]

Well there have been some straight up expensive "luxury" phones over the years. Apple in that regard is perhaps more in the BMW or Porsche end of the scale.