At least FB gives you some control over what you see (I've tucked quite a few "friends" into a dark corner, blocked some annoying persons altogether, tweaked how often I see updated from others) so it is bearable if not very exciting.
If I was allowed to vote for the most useless feature that would be Instagrams "stories". I am yet to see a single use of it that I found interesting or entertaining. The worst is that you cannot turn them off :(