All the interesting and complicated functionality isn't in the core CPU but in the peripherals and specialized computation. USB, WiFi, Bluetooth, GPU, memory/g

All the interesting and complicated functionality isn't in the core CPU but in the peripherals and specialized computation. USB, WiFi, Bluetooth, GPU, memory/gpu interface, hardware media decoders, .... Most of which is proprietary IP and heavily patent encumbered. An open RISC chip won't help with that.