there are billions of social media users
People will keep harming themselves, because it is easier than quitting.
I was once an avid facebook user, during a particularly difficult and lonely period of my life. I am surprised folks felt less lonely off social media, unless they then spent more time in actual human contact. Were whole families off for that week?
I haven't been on facebook for five years, but man is it hard to get information without it! Nearly all businesses around here have abandoned costly websites in favor of free facebook accounts to advertise hours, menus, inventory, contact info, etc. Fortunately, it takes nothing for me to drive over there and see for myself.
No surprise that the results were questioned when they came up with the undesired conclusions. We ought to see this as an opportunity to question all studies of human nature, because all data can be manipulated to get whatever statistics are sought. Use your own eyes to decide what is true. Get off social media and see how it makes you feel.