It is 100% about FOMO. The greatest pushback you'll get from anyone when you suggest voluntarily cutting off their social media accounts is that it's their way of keeping in touch/track of friends who they probably never interact with outside of watching their feeds.

Did you interact (like you know, two-way communication) with these people at any time in the last month? In the last year? In the last decade?

_Disabling_ your account, and deleting the app won't stop you from being able to log back in one day in the future if you want to look someone up, but in the mean time, you'll be living a blissful life without an ad-fuelled torment nexus simulating meaningful relationships.