I was interested until he brought up that matrix was just a reinvention of an existing idea. no, xmpp cannot do everything that matrix can. have you ever tried getting consistency of history in xmpp? it's absolute garbage. his warnings about the fediverse are on point though. I do wonder if matrix will end up suffering the same fate when Reddit offers to federate with them. The matrix protocol is already brittle as it is, and compatibility even between good faith implementations of existing servers is hard.

The main thing I understood is that once Meta joins the Fediverse we need to stand up for protecting our protocol standards, is that correct?

Great post by Ploum. Really sheds some light on how vicious these things can be and how federation will have to really push for openness and freedom.

Can anyone with expertise explain the structural difference between Matrix and XMPP?

Really good read. I was not aware of the history in such details, but the argument is very compelling.