I never stated that. I don't care about using Facebook to actively follow online personas of my friends. I see them multiple times a week, so I can find out their welfare then. For random people I'm friends with? Eh, less interested in the Tasty video they shared.
> wouldn't leavers report great angst from withdrawal
That's my point - that by not viewing life through a tailored filter, you have to deal with the less pleasant parts. As these are minor hardships and not major tragedies, happiness is coming partially from a sense of being able to "handle" things.
I am not saying this is explicitly where the happiness comes from, but if people quitting social media are reporting higher scores of happiness then either the metrics are wrong or the next question is "why". At which point, what are the factors that cause happiness, and how are those factors formed outside social media?