NFC is just a hardware standard for secure wireless communications. UPI is a payment rails (actually, UPI is a frontend for the IMPS payment rails, but, for all practical purposes, we can consider UPI to be a payment rails).
No point comparing a hardware standard with a payment rails.
But your question is probably based on your observation of NFC in the context of its use in with credit card, debit card and mobile wallet. So, the implied question is “Why is Credit Card not as popular as UPI in India?”
If so, I disagree. Popularity implies preference. Everyone prefers credit card but very few qualify for it. OTOH, UPI (and debit card) is a matter of right, so UPI / debit card are more widespread but credit card is arguably more popular.
I’ve answered this question in the context of credit card versus debit card at https://qr.ae/TWVGsP. Replace debit card with UPI in that answer and it will more or less answer your current question.