That particular underclass problem seems unlikely, relative to how much any 120 IQ human pales in comparison to any synthetic AGI or even domain-expert AI. The

That particular underclass problem seems unlikely, relative to how much any 120 IQ human pales in comparison to any synthetic AGI or even domain-expert AI. The real underclass would be humans vs. machines, which would 10x, 100x or 1000x IQ, perception, strength, dexterity... pretty much any measure. By the time we can make 120 IQ humans consistently, we'll be able to make 120 IQ machines consistently. And a couple years or perhaps hours after that the 120 IQ machines will be able to make 240 IQ machines and so on.