So far, I installed my own Matrix server (synapse), my own XMPP (ejabberd), yesterday I got semi-happy with my mastodon setup, and now I was just finishing some tests with ownCloud to see if I could replace Dropbox.
MediaGoblin is on my list of services to setup. I ran a basic deployment and checked some other instances of it before, but I didn't put it higher on my priority list because to me it looks like it focus too much on being a "community-driven website" instead of providing a solid service as a media-hosting/publishing/catalog system.
To me it looks like they are shooting for the wrong level of "decentralization granularity". Each instance of these services are aiming for a "community", and think that the people use the mainstream tools because they don't want to/won't manage the server.
The point they seem to miss is that this only creates another type of top-down organization. It would be MUCH easier for them to focus on a "single-user" system, and start from the point that the communication will work when the applications talk with each other.
To me this is why Diaspora failed, and Wordpress is still such a big part of the internet.
Another thing I noticed: the projects that really focused on separating client from server produced much better results in terms of UI/UX. With Matrix, I just had to setup the server, and then I could have the riot app just point to my instance. If by any chance a better client comes around, my instance would be untouched.