Pixelfed is such a great example of the flexibility of ActivityPub - it lets me follow artists on Mastodon, but instead of the mental whiplash of text and image posts mixed together in one timeline, I see artwork at the top level with replies shown as comments. Heck, I'm "commenting" on this post right now
Hard disagree. There are no separate social networks, and it is not the software that makes the network. That is the whole point of the Fediverse. I shouldn’t care about the identity of the servers, all I should care is about the having a common language and a way to identify the actors.
If a user can not post a picture on Pixelfed and other people can not vote on it, then it’s a shortcoming of the software, not an integral quality of the system. I could switch my Lemmy server to, e.g. Takahe with extensions to support voting and you would be none the wiser.