Google+ in particular was a spectacular failure, entering the world stillborn. At least some of the others on this list had their glory days.
It used to be great for that. You used Facebook to do your normal social networking, and still had a Myspace account so you could go down the rabbit hole of discovering bands from the local to the international level.
What happened to it? I don't even remember. They should have shaped it into a music-oriented social network. If they invested a lot of money into it, maybe they could draw people back from Facebook and even compete with them.
Too many people I knew had profiles with white text on a yellow background and autoplaying music. It was just horrible visiting their profiles.
I've always viewed this as MySpace's top feature and the direction away from this is why MySpace failed. The name even implied it was a users space of personal creation. Tumblr sort-of did well with similar ideas, but to a lesser extent.
Myspace is the only time on the internet there was a standard place to list shows that everyone was onboard with. The reason was because it was so easy to do so. Except for the date, city and genre all the fields were just text and you could put whatever you wanted. This meant that even bass players could figure out how to list a show.
When facebook first got the clear lead, most people still signed onto myspace at least once a week, especially everyone I knew in a band. The minute they made the change, they all stopped.
No annoying app/game spam which was a major annoyance on FB back then--I didn't want to grant god-knows-who access to my profile just to play a game or take some stupid quiz. And gee, look what happened with Cambridge Analytica and friends?
The other one was lack of a simple way to post to specific sets of contacts. Silly irreverent posts, photos, links, etc. went to friends. Daily life/bloggy type stuff went to friends and family. Things I wanted to share with the world went to public. Facebook never made that easy.
Plus I was already using their IM platform as GChat-cum-Hangouts on phone and desktop so no need to dick around with Facebook's IM app.
But regardless of how good or bad any feature of G+ (or any other challenger) was, the issue was the same: unless all of your contacts actively moved over, you were shouting into the wind.
The days of choosing your favorite webmail provider allowed competition in that space because they all did basically the same thing. Nobody else had to do anything differently. You just pick the one you like and maybe set up a forwarding address at your old one.
With closed social networking sites, you can argue that the only thing that matters is size of userbase. And if Facebook was the first to get not only the kids and the techies, but your mom, your neighbors, your barber, and your bartender, how many of those do you think will care enough about a cleaner UI or better photo hosting to cross-post or pull up stakes?
I don't even care about Google+ per se. I am bummed about some of the groups I was in who had to find a new platform, but mainly I just wish there was some way to accomplish the same thing while allowing people to choose their preferred service.