WhatsApp is one of the most used messenger applications today with more than 2 Billion users worldwide. It was found that more than 65 billion messages are sent on WhatsApp daily so we can use WhatsApp chats for analyzing our chat with a friend, customer, or a group of people. You can use your WhatsApp data for many data science tasks like sentiment analysis, keyword extraction, named entity recognition, text analysis and several other natural language processing tasks.
It also depends on who you are analyzing your WhatsApp messages with because you can find a lot of information from your WhatsApp messages which can also help you to solve business problems.