As these sites / services evolved I've found they are becoming more unless and loaded with bloat and complicated settings.
For example I liked the early days of facebook and its simplicity. I also liked instagram without all the jazz that it has now. And linked in, well I never really used it but I'm sure there is something that really worked at first but slowly was degraded from scope creep.
FB - Simple wall / status / messages / Closed community
IG - Take a photo / tag / post
LI - ?
IG - Stories. It's a great way to stay up to date with friends
LI - Posts and Messages. LI's limited messaging feature is actually great for sending/receiving opportunities without too much spam.