Facebook wants you to designate friends as Trusted Contacts who can restore access to your Facebook account. Facebook doesn’t say why you might have trouble logging in. Account recovery processes have a long history of insecurity. Account compromises often occur as a result of social engineering attacks. Users will probably be less likely to drift away from Facebook when their friends have entrusted them with the keys to their accounts, Facebook says. With trusted contacts, there’s no need to worry about remembering security questions or filling out long web forms to prove who you are.”]
Source: https://www.darkreading.com/attacks-breaches/facebook-turns-friends-into-it-support