Already Freakonomics noted/claimed that reading to kids makes little difference to educational outcome, whereas having lots books at home matters. The following explanation (taken from https://abcnews.go.com/WNT/story?id=1633286&page=1) was given:

"Well, no," he continued. "Much more likely is that any family that has 100 children's books in the home is likely to be pretty highly educated to begin with, is starting out with a pretty high IQ, and values or treasures or rewards education to begin with."