Because some answers cannot be summarised. A cancellation policy, a data residency statement or a compliance answer has to be exactly right, and paraphrasing it introduces risk.
An FAQ is a question and answer pair written directly, used verbatim when a matching question is asked.
FAQ answers are returned as written rather than reworded, and take priority over articles and crawled pages when the question matches.
A refund policy answer that legal has approved is entered as an FAQ. That exact wording is what a customer receives, every time.
They will not stretch to cover a variant. An FAQ answers the question it was written for; a near-miss falls through to the other sources rather than being bent to fit.
They outrank other sources on a match, so an approved answer cannot be overridden by a stale crawled page.
On meaning as well as wording, with the threshold visible.
Yes, scoped like any source.
Yes, with frequency, which shows what to write next.
Fourteen days, every module, no card. Or half an hour with someone who will run it on your own records and tell you where it does not help.