By this assumption, surely everything that can be invented already has, right?

Within telecom pricing strategy? Yes, given current technology.

One can go back in the lit to Bell Labs research in the 60s for all the pricing strategies. Jean Tirole fleshed most of it out with help by Jean Rochet.

Source: Economist, network industries are my object of research

It's very anti-profitable for them, because it removes their ability to suppress functionality of your phone in order to sell it back to you.

First rule of phone company: why market when you can monopoly?