You are right. Upi is something unique to India so WhatsApp pay in India can’t leverage the Fb pay infrastructure.
However, it can elsewhere including the us.
> can’t leverage the Fb pay infrastructure
According to “How it Works”, it supports multiple payment methods like PayPal & Credit cards - I don’t see why UPI couldn’t just be another option on the list specifically for India.
Re:Facebook Pay
by shubham_sinha on Sunday February 13, 2022 @12:03AM
(#30319380)
WhatsApp pay is just another UPI app
It's confusing since the page says "Facebook Pay is a seamless, secure way to pay on the apps you already use". And whatsapp is listed as one app.
Maybe it's entirely different from UPI based Whatsapp pay
[] https://pay.facebook.com/availability/