What an astounding post—this feels like the situation today. (And sure enough—FOAF, XML-RPC and SOAP all went their way.) It is pretty surprising that Microformats have somewhat survived—the u- and p- prefixes, figuring out how to nest elements, complex rules like you see on the Indieweb authorship page.
I wonder what drives the complexity of something like ActivityPub. Is it a kind of premature future-proofing? Is it just a desire to load the thing with features? I especially wonder about something like FOAF, which should be conceptually simple.
Really appreciate the conversation, Manton.