This may be because Ascendance of a Bookworm appeals to a more diverse demographic than SAO, as the latter appeals more to men and a much younger demographic, while the former is popular for both men and women, as well as older and younger viewers.
Much like the Akiba Souken poll, SAO finished in a much lower ranking than expected, while Ascendance of a Bookworm took 1st place.
So, which light novel-based anime was your favourite from 2019?
3 – Is It Wrong to Try to Pick Up Girls in a Dungeon?