Its kind of amazing how often people make judgements based on extrapolating demographic trends over much longer terms than there is any reason to think that they will hold, and then as soon as they fail turn around and do the same thing based on the new demographic trend.
Encouraging births isn't hard if a government decides its important.
OTOH, most of the arguments I’ve seen for it actually being important (in the near term) are the kind where you scratch the surface and underneath is pure racism, so I’m not all that concerned.