If you use protobuf/gRPC anywhere in your application, text format protobuf. Writes like JSON, but with a clear schema, a parser that already exists in most languages, and has comments.

I think it’s more that AIM was the only other decent sized player in chat that actually played along with federation. With nobody else playing ball and everyone building their own walled gardens, it didn’t make sense for Google to continue to invest.

As someone who has written XMPP code, the protocol is also not pleasant to work with as it’s all XML. IIRC, features like presence and read receipts weren’t initially part of the protocol. That said, I still think extended an existing popular protocol is better than making a new one.