Earlier quoted context omitted.
Please explain how, because if stupid people have more kids, there will be more stupid people.
The heritability of intelligence and other factors is highly variable. You want people who will care diligently for their children to have them. Not people who will be largely indifferent to them, whether they're smart or dumb. The Musk 'I'll have ten and scatter them to the wind with bags of money, the odds will take care of the rest' strategy is not really one that works out well in real life.
Your second point is true, of course.