I personally believe there is no way for them to succeed. If they were acting in good faith the actual incease in the number of intelligent people, who would recognize cruelty when they see it, would tear it down. If they acted in bad faith, which they most definitely would, they would fill the world with these idiots.
There would be a lot less creativity and innovation if Eugenisists had their way. Think about it. If everyone was the same, where would new and innovative ideas https://www.mckinsey.com/featured-insights/diversity-and-inclusion/diversity-matters-even-more-the-case-for-holistic-impact)? Even worse how many ideas would die with their people? Who are the people we are getting rid of?
Racially motivated eugenisists have been around for ever and kill civilization not help it (genocides). Gender related eugenics happen and it’s usually women that pay (https://www.investopedia.com/terms/o/one-child-policy.asp). How do messure disability and the impact on ones life? IQ tests messure the ability to regurgitate facts not actual intelligence (https://pmc.ncbi.nlm.nih.gov/articles/PMC6927908/).
I’m sure I’m missing some, but this os more than enough to show if Eugenisists have any say we all will suffer.
IQ measures the likelihood of someone being successful based on an age category. It has little to do with actual critical thinking. In a society that only values IQ it becomes meaningless because its only feeding off itself.