Ethnic people generally very happy to see you in their traditional clothes. So become Roman when you are in Rome. Further, traditional clothes are associated with their way of living. Ethnic dresses are their identity and show their living manners, cultures, food and other values. Now a day world is like a small family so you should know the different cultures and clothing manners of different societies.
It is helpful for a many purposes such as tourism and fashion designing purposes because if you are a travel agent, you should have the knowledge various tastes and inform to their clients and if you are a tourist, you should also have the information to adjust there and to learn from them and if you are a fashion designer or want to go in this industry you will learn a lot and can create unique designs.
Clothes are unspoken language and speak about you and your behavior without speaking any single word.