"There is much software out there and yet to be written for IoT that doesn't need anything more than 32-bit, also given what was achieved with 16-bit architectures 32-bit for some is an overkill, it would seem the time has come to separate the architectures and have 32-bit only and 64-bit only chip families."
8 bit CPUs work fine for much of the stuff IoT tries to do. How many bits do you really need to switch a light bulb on and off? Or even for dimming the light bulb?