WhatsApp Pay has faced significant challenges in gaining widespread adoption in India, despite WhatsApp's massive user base of 500 million in the country. According to a report by Rest of World, regulatory delays in its full launch, coupled with limited product enhancements and marketing efforts, have hindered its ability to penetrate India's burgeoning $3 trillion fintech market. The platform's struggle highlights the complexities of navigating the Indian financial landscape, even with a substantial existing user base.