There's not much we can really do about it I'll be ecstatic my grandchildren are as smart as I am. I suppose if I marry a woman ≥ to me in intelligence then there won't be a drop in the next gen if it follows the law of averages. Then the more children I have the more difficult it'd be to make sure the same for them. After 3 generations I really have no control there either.

Honestly what dooms us is that few smart men want children and few smart women want to stay at home. The former stays single for as long as possible and will be dragged kicking and screaming into fatherhood. The latter will have 1-2 kids and be scrambling forever after to pay for childcare and activities.

To be honest I can't begrudge people for not wanting children, as it's a base, earthly instinct and some people want to go beyond that. Half the reason I want them is that I want to prove I can do a better job than my parents and the other half is I genuinely enjoy interacting with children.