Such as?

Also FB private groups that may be of interest to the user.

For example many football club-related groups are private for obvious reasons, and, as such, getting kicked out of FB also means getting kicked out of your local supporters' forum where the online discussions happen. Yes, people from that group also meet irl, but not all of them attend those meetings and those meetings happen, at most, once every week (after the football season starts). For example we're out-season now but this is also the time of some of the most heated and interesting discussions, because right now we're in the middle of the transfer season.

Twitter throws up a jarring sign-in wall if you scroll down more than a few tweets now.

Instagram.

IG has always hobbled the browser version and always restricted access without an account.

It’s also pretty easy to just set up a new account on a different machine.