According to google, that is not correct. They levy a 30% fee on all Play Store transactions for apps and IAP. I've seen articles that say they are cutting the fee to 15% for businesses with under $1m revenue, but that's not what the support page says.
To use Google Pay this way, you'll have to find a payment processor that handles local taxes and all that. As a developer from a country where Stripe isn't available, it's a significant hurdle.
https://support.google.com/paymentscenter/answer/7159343?hl=...
Buying physical goods and services may not count, in the same way that they don't count on the Apple App Store.