>>43081
I think these ideas comes from the time when they were sure humanity's population boom will keep going. More people will need more resources.
Back then a family kept producing children, because child-mortality was high, people kept reproduce because that was the only way of ensuring survival. But with a couple of simple changes child-mortality could be pushed down. It wasn't something mindblowing high tech thing that does that, but first doctors realized they had to wash their hands with hot water and soap after butchering cadavers, mothers have to keep a better diet while pregnant, and overall just a slight more calories, and bit more hygiene went a long way of ensuring that most kids will reach adulthood.
Then with the rise of standard of living, the population boom halts (unless some dramatic happens like WWII, which gave a boost for a while). Now we don't need to rely on the production of children in large numbers to ensure survival.
What if in the future we find other ways the complement this or develop on it. What if we could ensure longevity for the individual, extending life expectancy, or preserving consciousness in some other form. Cushioning ourselves from harm better. Here I don't want to go in the "getting soft and weak for the lack of challenge" direction.
Right now humanity could do just fine with the fraction of the population now we have, I dunno how the African boom will pan out, supposedly the Chinese and the Indian slowed down I think. How many more people we're gonna have here? Do we ever need a giant space what a Dyson sphere could offer?