Let's make this clear: Spanish population only grows because of immigration. We have one of the lowest birth rates in the world (see https://worldpopulationreview.com/country-rankings/birth-rate-by-country), but allowing immigration has somewhat contained our population decline. Without immigration, our pension and health systems would be unsustainable, unable to cater an aging population. So we have immigration to thank for what you see in that image. Countries with low birth rates and low immigration (like Japan) are actually doomed.
What happens if all countries were doing well enough for immigration to slow down? Like not having constant wars and dictatorships?
What happens if your country becomes less appealing to immigrants, or gets a short surge of anti immigration leadership like the US?
If an increase in population is necessary to support retirement and your own population can't sustain that, then you are propping up a system that requires other countries to be worse off. That cannot continue indefinitely.
But I’m not proposing in any way immigration as a path to solve the problem of aging population. That interpretation is solely on you.
I’m only saying that immigration it’s just a phenomenon that happened (and it’s not happening at the same rate as in the past anymore), and that I’m glad it happened, because if not, we would be in real trouble really soon. I’m just thankful for the immigrants to this country, because it’s them saving our asses (in contrast to people thinking they’re a problem).
The causes of our aging population are other, and the real solution requires actions that I wish politicians tried to solve. Immigration was just a temporary fix, that we should be thankful for, but it’s not the solution to the problem at all, nor am I proposing it as the solution.
You started your comment with “That seems to suggest…” Well, no, I’m not suggesting anything more than what I said. Just that. And I don’t feel the need to explain anything further. Cheers.