The good thing about trying this is people would definitely notice the increased bandwidth usage of their phone streaming audio in real time, all the time.
Not to mention most phones heat up when they stream anything.
"0/5 stars. This product doubled my bandwidth bill."
No one writes sane enough software (or even freaking documents) to make that doable.
Right now the internet is basically built on a bunch of "gentlemen agreements" to play fair, all the way from BGP down to ISPs ("please filter egress, pretty please!") to end-users ("please don't actually use all of your bandwidth because we're overprovisioned!").
Of course, the fee has to be tiny. For example, you don't reconsider hydrating yourself to save some money. But you may reconsider leaving your heater on 24/7 when you can just wear a jacket indoors. It would have to be priced similar to that. Though other things will have to change as well, like we'd need the ability to shop between ISPs in a region.
Most people are already paying per byte, but in the most roundabout marketing-mislead way and I see that as a problem that only really helps ISPs. Imagine if it was a fully commoditized utility instead.
On the other hand, look at the effects of the status quo. People have so little insight into their usage that you can buy enough residential botnet egress to take down any site for $5 which empowers centralization like Cloudflare DDoS protection. I suppose you either don't see this as a problem or you can think of other solutions.