Several elements are well-known that still don't explain the large differences in cultures; flourishing is a cultural phenomenon.
Progress has been mixed. The supply of educated people has continued to lag behind advancing technologies, as flatlining results in PISA starkly demonstrate. Most countries have struggled to close the equity gap. More broadly, the Human Capital theory has itself been progressively undermined. The HPST group has reflected on three particular critiques.
The first is that the drive for economic growth, on which the Human Capital theory is premised, has been secured at too high a price. In many countries, we see widening wealth gaps, disruptive migrations, and increasing social fragmentation."
https://www.oecd.org/content/dam/oecd/en/publications/reports/2025/11/education-for-human-flourishing_cb043494/73d7cb96-en.pdf