I found this policy note that provides a decent overview of the research linking energy and educational. Results are mixed. I am still biased towards the link being there (study finding no link studies 200 students over 3 months, whereas the study finding a link was over 3 years with 10,000 students).

https://www.theigc.org/wp-content/uploads/2017/06/40418-poli...

And if the people educated can leave for better lands, they often will. There aren’t easy ways to prevent that.