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.
I'm the oldest of 11 kids, and I'd like to hear more of your thoughts on this. I agree with your second statement, which is why conscientious people should have kids.
Well, hello! I am also the oldest of 11 kids; I rarely encounter another like me.
One of the many reasons I have carefully avoided making any children over the years is that I already had my fill of child-rearing by the time I left home, through looking after my younger siblings. I wonder what your experience with this was.