Don't know if it's still this way, but I had the exact same experience with the XEPs a decade ago. Even message history is an extension, but at least it has bro

Don't know if it's still this way, but I had the exact same experience with the XEPs a decade ago. Even message history is an extension, but at least it has broad support. File transfer was much harder to get right. The servers (ejabberd included) also all defaulted to a simpler but less secure config, so I would've appreciated a writeup like this post back then.