A study of US public libraries found that library capital investments increases children's attendance at library events 18%, their checkouts by 21%, and visits by 21%. It translated into improve test scores in nearby school districts. A $1000+ per-student capital investment in local public libraries increased reading test scores the .02 standard deviations (not significant for math scores.
Gilpin, G., Karger, E., & Nencka, F. (2021). The returns to public library investment. Federal Reserach Bank of Chicago.