Of course, by statistics no one of us is Plato or Roger Bacon. I'd agree that a problem with the modern world is an ideology of (objectively) crappy career or climbing some fake institutional hierarchy being a worthy substitute for family. I myself do believe that a family is one of relatively easiest (but still hard and demanding) ways to being happy [1].
I also see a lot of people here overcorrecting and arriving at some strange worldviews.
Some people are childless because of objective circumstances: what are they, damned by God via predestination to unhappiness? In the Catholic world, they have been, esp. in the olden days, a lot of childless priests, monks, nuns. If you want to at the same time value tradition and not reinventing (quoting parent) and "evolutionary DNA survival", you either have to somehow condemn Catholicism and Orthodoxy [2], or start adding some epicycles to your philosophy.
Oh, and on topic: I believe being happy requires working for it. Maybe for "smarter" people their allotted amount of work is higher. Don't know if it's nice to hear, but sounds true to me.
[1] Maybe one lure of career is that people are culturally accepting of life at work being terrible in many ways, while a poorly constructed family (one or more immature people etc.) scares people off pretty fast. Maybe because it's a more total institution and harder to escape.
[2] Which would be the OG Protestant way.