My gut says these SoCs are being sold below cost.
IDK, even rpi4 is still on 28nm which is the cheapest process per gate right now. And they really have very few gates allthibgs considered. I could absolutely see somewhere between $5 and $10 at cost, not counting R&D.
But marking your engineers' spare time as donated since your contract owns everything they produce anyway, and selling chips at cost and marking the profit as a donation when you were probably going to take a loss on them does in fact net you ahead.