Same problems with LinkedIn, I've never managed to close a deal that has gone through LinkedIn, I've partnered up with people I've met on LinkedIn and they were the worst partners I've ever worked with, other than that recruitment spam everywhere - luckily my phone number is not on LinkedIn, so not getting phone calls.
I've recently re-activated Facebook after almost 3 years absence from it and it feels like a ghost-town with lots of baby pictures everywhere and almost no interaction - with 500 friends in my friends list, I would post something and get maybe 3 likes and very little other interaction - it used to be long conversations and debates that would keep everyone hooked. Maybe it's just that everyone on Facebook is aging and not into online debates anymore and just passively consuming content? These days it's a glorified address book.
Google+ I still use actively to communicate with Google Engineers and people I don't know in general (mostly developers), but other than that, it's just for cat pictures.
Ello I've tried for a bit, feels like a site that was built by a 10-year old learning how to build websites - so eventually ditched it.
Twitter I've abandoned as well, too much noise and spammers everywhere trying to get your attention with DMs and @Mentions.
Instagram / Pinterest seems to be all about popular people trying to get a following, so removed my account, didn't quite get why anyone would post pictures of their lunch and then have people ooh and aah about it.