The solution to that isn't to dumb down everything, it's to lift everyone else up. Mandate that adults be educated and provide remedial classes at community colleges for free. Failure to comply results in losing the ability to hold gainful employment or vote. Anonymize testing and tie test results to social security numbers.
It's either do that, or allow civilization to collapse while other countries that do force their citizens to be educated flourish.
We really need to push for the feds to step in and start constructing government housing against the will of the NIMBYs and local and state governments then.