A good analogy might be the Black Death: it didn’t destroy Europe, it changed priorities, freed the serfs, started valuing labor more, and ultimately led to a stronger Europe in the future.
Our "plague" "kills" the young and productive - by their never being born in the first place. We are headed for something we have never seen, ever: a society dominated by old people in pure numbers terms.
The worry is that it is a design for stagnation and decay rather than greater strength. (There won't be money or people to maintain infrastructure because the elders will demand healthcare.)
I don't know what will happen and nor does anyone else really.
South Korea and Hungary (among many others) have tried paying people to have children, without success. It pulls a few births forward in time, but then the birth rate declines again.
There is something more fundamental going on.