In India, a swim suit is known as a swimming costume. When I lived in India, my apartment complex had rules that people must wear swimsuits that were in line with Indian modesty conventions. That meant, women were required to wear one piece suits and not bikinis. I later learned that this is a general practice in most parts of India. I believe, when visiting a country, it is important to remember that we are guests and, as guests, should conform to the local conventions. It’s a matter of respect. To not do so is akin to slapping the hosts across the face.
Every Western woman I saw at the hotel pool was wearing a bikini. I am sure that some may not have known of the Indian conventions. It is not difficult to Google and learn of local practices. Others probably knew but just didn’t care. These people are better off staying at home.