I think after G+ we can no longer gather at one place anymore. We'll have to go separate ways and it's inevitable. If you're like me who always open an account on almost every social media available (except facebook of course) that wouldn't be a problem but not everyone is willing to do that. Not to mention the hassle one would have to face to maintain presence in multiple places that even I am struggling to keep up with it too.
Right now most (like 4/5) of my Japanese contacts on G+ have migrated to MeWe and found themselves comfortable settling there while many of my Chinese contacts seem to have 'retreated' to homegrown social media like Weibo and QQ. So if I still want to keep in touch with them I have no choice but to join them in those places too instead of 'forcing' them to follow me here or any other social platform I'll choose as my online home later.
Oh no, no Pluspora for me. While I do root for Diaspora (and have an account at joindiaspora almost as old as G+ itself) I think Diaspora is a bad choice to become a successor to G+. The inability to edit posts/comments as well as the developers' weird motivation to oppose the editing ability is enough to put me off. Maybe I'll become active again once the post editing feature is added. I think we'll see MeWe opening up for search engine indexing before that happens though.