The author is over simplifying evolution. A trait maybe passed on to children even though the parent isn't displaying it.

The easiest example of this across many species is homosexuality. As it seems obvious that it would reduce an individuals chances of having offspring. https://www.newscientist.com/article/dn13674-evolution-myths...

There is the added complexity that some positive traits are tied to negative traits. Meaning if the gene stops getting selected the positive trait goes away with the negative one.

And then there is culture. It is clear humans have become the dominant species of our planet (at least for now) and it is our culture and the technology it supports that enable this.