For usage with many IOT?
The better question is where are the MU-Mimo clients? I have only seen a few phones that actually support it…
Most Samsung flagship phones have mu-mimo. The S7 was the first 4x4 mu-mimo smartphone. Apple does not have any offerings for for phones, Air2 had mimo support.
For IOT use, not sure what the benefit would be? Most IoT devices do not have much processing power and bandwidth is burstable.
For density use it would also be beneficial but not really for home IoT. Things like a media server/tablets/smartphones and maybe new laptops.