People are abandoning all belief in an eternal existence, and accepting the scientific materialism that tells them there is nothing after this life. So they stop having babies.
But the same scientific materialism constantly interprets all urges, impulses, and processes as the drive to pass on genes, subliminated.
So, you’d think that as as we are liberated from the illusion of religion we are freed to act more rationally, which the materialist would argue is to propogate the species.
But the opposite seems to be happening.