https://data.worldbank.org/indicator/NY.GDP.PCAP.PP.CD?most_...
WTF happened in Japan? All the above countries have their own demographic collapse as well BTW.
Also, regarding sibling comment about relevance of PPP metrics: I challenge you to come to Czechia or Poland - the quality of life can really surprise you. Those are, for example, the two countries with the lowest unemployment rates in EU. We have nice apartments and houses (with photovoltaic panels and heat pumps, mind you), drive nice cars, have good healthcare and free higher education.
Unless I get a $1M+ per year offer from a FAANG in Silicon Valley I feel like no country in the world can offer me a significantly better standard of living.
Most of the Soviet Bloc type nations you named had reasonable fertility rates under the USSR, only collapsed once the USSR collapsed in 1991, and are inching back up again. Japan, by contrast, never had a particularly great fertility rate post-war. Then it just collapsed in the 1970s and simply kept going down. [1]
Fertility rates just determine so much. With a good fertility rate companies grow naturally because their market size is constantly naturally increasing. And vice versa for poor fertility rates. It also determines the overall age distribution of a population, such as how in Japan now 10% of the population is over 80. When an ever larger chunk of your population is leaving the labor force with not enough people to replace them, and then an even smaller taxpayer base to provide the social benefits necessary to sustain these people in their elder years - everything just becomes completely unsustainable.
And, again, none of this will ever get better such as, for instance, when the older people start passing en masse. This is because fertility rate determines the ratio of distributions within a population. You can see this quite clearly in this [2] population pyramid. The only solution is for them to suddenly start dramatically increasing their fertility rate.
[1] - https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...
[2] - https://en.wikipedia.org/wiki/Demographics_of_Japan#/media/F...
In all other contexts would you also say gdp per capita is a metric not worth considering? If not then I humbly question the value of your statement.
(edited)
At the risk of being out of my depth: You only need a few seconds to look at the per-capita list before finding yourself asking "wait, why is THAT country so high up?". Again, useful info can be inferred, but it doesn't put the country above others in other important lists, which is what people usually imply and use it for, on topics not strictly related to economy statistics.
I guess I would avoid updating my beliefs too strongly when a measurement I generally find quite useful (in this case gdp per capita) does not perfectly map onto a more nuanced view of the world! As you say, it's only a single data point.