> Thanks to using a common protocol it's possible for users across these platforms to communicate with each other. It's possible to follow content, reshare it,

> Thanks to using a common protocol it's possible for users across these platforms to communicate with each other. It's possible to follow content, reshare it, leave comments, etc. So, instead of having a bunch of walled gardens you have an actual ecosystem of different platforms. I can understand why you believe this, because it's part of the ActivityPub marketing, but it simply isn't true. ActivityPub is extremely loosely defined, and the protocol it builds on, ActivityStreams, places no limitations on the type of data that is transferred. What this means is that in practice you can only federate with other instances of the same software as your homeserver without degradation. It's very hit or miss. The best cross implementation communication comes between Mastodon and Pleroma, but Mastodon is more popular and implements a number of other protocols in addition to ActivityPub, so to keep up Pleroma actually matches their API, not the protocol. The other implementations that you mentioned mostly federate among themselves. Sadly this undoes many of the benefits you've listed. You do very much need a Lemmy server account, a Pixelfed server account, a Mastodon account, etc, if you want everything. And you have to pick a homeserver each time, and it isn't easy.