Or, again, make it easier to raise kids. Subsidize childcare, or even better, allow zoning that stimulates community development so people have free childcare in their neighbors or extended family living nearby.
[1] https://www.economist.com/graphic-detail/2021/07/01/which-co... [2] https://www.euronews.com/next/2023/03/06/childcare-puzzle-wh...
I can't comment on Iceland.
However, South Korea has one of the most crushing work cultures in the world, with insane work hours. Most people are not even in a relationship yet alone with kids.
In Portugal you have a huge problem of disposable income. Median salaries are insanely low and stagnant when adjusted to COL. To the point that by now most former 'Iron Curtain' EU members have surpassed Portugal in workers income both adjusted and absolute.
Now, I am not having children either, but I will not deny that even in the best of countries, when controlling for all of these factors, people still aren't having children simply because they have no want or need of having them. That's it, that's the reality. Now it is an uncomfortable truth for many, but many people nowadays, me included, just don't want them, for no particular reason at all.
Apparently, married people are having kids at roughly the same rate as they did decades ago. However, fewer people are getting married and far fewer kids are being born outside of wedlock.
These are not necessarily negative developments, at least at the individual level, but they do point towards a significant change in human culture and society: increasingly, only people with a strong intrinsic drive to have kids will do so.
I don't think that we can predict the effect of this trend a few generations from now.