Evolution doesn't work like that. What we have here is a dead end. For whatever reason, this system isn't advantageous from an evolutionary perspective, so we don't reproduce. That's natural selection.
Will we discover life extension technology before we stop having children and humanity simply dies off? Between Altered Carbon and Children of Men, I feel like that's a book and a blockbuster movie waiting to be written.
If conscious machines are even 80% as smart as us and 1) never die and 2) can replicate memories, why would anyone have children again? I'd imagine we'd desperately try to build brain uploads or be intolerably jealous of our eternal life robot kin.
We're going to be so jealous of the robots. They'll have everything and never die.
The men are playing Fortnite. The women are on TikTok and Instagram.
Babies went off trend so we could collectively do dopamine maxxing as a species.
Evolution didn't anticipate this.