How does *ACL conferences acceptance work [D]

Even after getting ARR reviews and a meta review, how is the acceptance decided at the *ACL venues, because I have seen meta review 3.5 getting to findings and 3 getting to main or even getting rejected. Then what is the purpose of the overall score and recommendation? What do the conferences see when deciding? Do they only care about the metareview and their comments, or the whole set of reviews as well as along with the track in which the paper was submitted. Anyone knowing the process please kindly tell.