With the current pace of change, having children may no longer be the obvious winner it has been for all of history, but it might still be...
Does that mean we shouldn't just bother, absolutely not, we are given this gift of experiencing life. Something rather than nothingness...etc. But we can do with a little more perspective on how utterly inconsequential we are in the grand scheme of things. Having kids seems consequential in the context of human existence, but when human existence is inconsequential (there is no lasting impact or transmission of information beyond our temporary side-effects on the environment) it puts our existence into perspective.
The fact that we've hit upon a certain arrangement of matter which yields consciousness and the ability to manipulate the matter around us is something which seems worth preservation.
I contain the information for how to give life to inert matter. I've done it three times now, and I think it's worthwhile.
Yes, it is more meaningful to have kids than to build a stonewall.
Aren't walls inventions of man, as such, an effect caused by man. How can an effect (invention) of man be equated to the inventor?
Do you compare the effect of human freedom to the effect of unconscious matter in history?
We're very far from where we started. We're here because of both people that had kids and because of people that built stone walls. In many cases they were the same people.