https://www.cnet.com/news/facebook-ceo-mark-zuckerbergs-vision-for-the-future-focuses-on-private-messaging/

Zuckerberg said he thinks people will still post publicly on the world's largest social network but that a growing number of its 2.3 billion users are using messaging apps like Facebook Messenger and WhatsApp to converse privately with their friends and family. They're also sharing more photos and videos that vanish in 24 hours through a feature called Stories. 

In a few years, though, Zuckerberg expects that Facebook users will be communicating more on Messenger and WhatsApp instead of posting publicly on the social network's News Feed.