It's about flippin' time. I was able to do this on Android (and older flip phones) with AT&T and Verizon for years.
While I usually prefer to buy the apps myself, there are a few cases where billing it to the carrier is far better. In particular, when I first got my work phone, I needed to purchase and install a special mail app (for $20) for connecting to our corporate mail servers. I could have done this the hard way - fill out a purchase-order request, get it approved, then charge the purchase to my corporate credit card, then file an expense report to get reimbursed. Or I could do what I did - bill it to the carrier, where it just shows up on the bill that the company paid as a part of their normal expenses.
(Yes, I realize that the ability to do this has the potential for abuse. All I can say is that I don't abuse that privilege. I only do this for apps that my employer requires me to install.)
And it's no different from what other platforms have supported for a long time. The Google Play store supports this. And my ancient flip-phones all supported this, although in that case, the carrier was running the store.
What carrier are you referring to? I don't know of any that charge interest or impose late fees for non payment of your bill. If you don't pay the bill, they cut off your service. If you still don't pay, they send a collections agency. They are not a credit company.