Intentionally lowering IQ might seem to be a solution to a controllable population. But at what cost to the elite? Look at European Monarchy and the results of a too finely-bred social group. Now they've got leaders who don't even breed.
It's interesting to speculate what the end game is. I fear the future of mankind is Idiocracy.
The reason is this: I believe the rate of technological advances and human knowledge doubles every generation. With this rate of trajectory, humanity is close in the realms of genetic engineering and quantum computing to create completely new virtual environments.
For instance, what good does it do to import low IQ people when the advent of gene therapy in the regions of brain research will eventually be able to diagnose and apply solutions to increased brain growth and/or cognitive functions? Likewise, what use is it to promote historically disadvantaged (read: losers) races, genders, religions, etc, when the same kinds of genetic applications will allow people to pick and choose any style and/or orientation subject to evolving standards of beauty? In other words, a few generations from now, everyone may very well choose to look like blonde Swedes.
Secondly, massive, almost unquantifiable leaps in computing power will render null the need to actually experience something as the benchmark record. IOW, I'd guess 80% of energy consumption is just getting physically to and fro, when it can easily be replaced by simply virtually "being there" in mind & spirit. This of course could extend to any human activity, whether it be scoring tail, traveling to Europe, skiing down the Rockies, etc.
Finally, combine both advances in DNA knowledge of how the brain operates along with sufficient computing power, and we will have an entirely new species of mankind. And this version will be able to take to space to explore the stars ...
Anyway, the global elite aren't really that smart, because they're not thinking in terms of human potential. Rather, like any plodder, they're stuck thinking within existing structural constraints: Euros/Americans consume too much, they need to cut back. Oh, look, they're rioting again and refuse to listen to reason. Well, then we'll swap them out for someone who will listen to us - that will fix their wagon. And so on.