The platform fee for the IBM PC is zero. The platform fee for notorious quasi-monopolist Microsoft Windows is still zero. That is the standard to which all other platforms should be held.

There is talk about the cost of designing and manufacturing the phone, which is irrelevant, especially in a world where users frequently buy new phones every two years. That cost should be borne by the purchaser of the phone.

Now, the ongoing costs of running payment systems and app stores are more significant, and I think it's reasonable to argue that they cannot be zero, but we should have a go at determining them in the market.