Having just bought a new camera after a couple of years away from photography (save for iPhone snaps) it strikes me that there is a gap in the market where Flickr once was.
I used to use Flickr alot and in the past have paid for pro membership more than once. The groups and communities were great, comments on pictures were plentiful and at times helpful, as well as being able to search for photos taken with a specific body or lens, somewhere to have an off-site copy and of course to enable bb code to be copied and pasted so that photos can be displayed on forums such as TP.
Instagram does have a sort of community feel, but it seems as though it is more about viewing one photo at a time in your ‘feed’ and the comments seem to mostly be about reciprocation - a like for a like.
Facebook does of course allow sharing of photos amongst friends and again there are groups that can be joined. They seem to do something pretty hideous with compression when the photo is uploading.
Finally, there are many ways to host your own websites to show off your portfolio and even gather sales from the photos if you’re lucky (or talented) or both!
I guess it does come down to what you’re trying to achieve - for me, it’s a case of resigning myself to having to use all of the above rather than one specific solution. Having to use multiple sites and services does make my ocd twitch though - feels very cluttered and disjointed.
Don’t get me started on the Lightroom subscription model