You know what's funny? LinkedIn is supposed to be a 'professional' social network (Microsoft owned) and a friend of mine was asked to add a phone number 'For security purposes'. I knew this was suspiciously involving 2FA SMS + a bonus of spam callers and I told him to press "Not Now". Whilst the world is moving to U2F and time-sensitive codes, a security system using SMS 2FA is now equivalent to a single PC running Windows XP in a bank.
But its not just LinkedIn. Its a huge list of major companies including some FAANG ones too. Oh dear.