That was also concluded by Hans Rosling: the higher the education of people, the fewer kids they have. Best way to address overpopulation is by increasing education worldwide. https://www.teesche.com/bookshelf/hans_rosling_factfulness
He has presented hours of thoughts on data spanning multiple decades from countries across the globe and comments identified correlations.
Education being highly correlated with reduced population growth is a data confirmed observation, and not a declaration of prime causation.
But then wonders what the drivers are.