Identity verification shows other members that a real, checked person stands behind an account. It is optional for buying, but you must be verified to publish or edit listings, start auctions or answer buyer requests with a price. It also raises your Trust Score, and buyers and sellers rely on it.
The team may remove verification if documents were fake or belonged to someone else, if the account is taken over or transferred, or after a confirmed fraud case. Submitting forged documents leads to suspension and may be reported to the authorities.