A fleeting thought related to the eventual successor for this part of the Web:

Is federation (in the style of ActivityPub or Matrix) worth the technical complexity?

What's the "bare minimum" protocol that enables federation but is also as simple as possible, such that there can easily exist multiple independent implementations?

RSS seems to come close for public stuff, and e-mail for private communications. Matrix's model is nice but it's wrapped in many layers of HTTP boilerplate. ActivityPub is kind of the worst of all worlds.

Where, then, shall go the fan of federation who doesn't like using others' software? Implementing everything from scratch is just asking for pain. Creating a new protocol goes against the principles of federation, where the protocols exist via consensus, and swerving away from that is pointless.

The search for an answer continues.