> I think there's also a tendency for everyone to want to do their own CPU now.

I mean... I think it's the opposite. There was a time when Qualcomm, Samsung and Nvidia had their own microarchs which they used in most things. Increasingly they're back to ARM-supplied designs now.

I suspect this is partly because the ARM designs are adequate these days, but also because phone CPUs just aren't that competitive anymore; the iPhone is enormously faster than any other phone, and consumers do not care about this at all, because the other phones are, generally, Good Enough.