I don't get it. XMPP had MEGOLM, cross signing, decentralized chat rooms, good iOS support in practice, very simple sync of e2ee chat history, ... 20 years ago?

> spitting on other protocols (or not even acknowledging their existence) without a technical reasoning (Matrix could have been a "simple" decentralized room extension of XMPP or any other established protocol) ;

This simply so wrong: Matrix was created exactly because if the failure of existing protocols [0]. And the mentioned extension was one failure in their mind.

[0]: https://matrix.org/faq/#why-has-no-one-done-this-before%3F

And imho it was the best thing to do. You don't repair a car if repairing costs much more than getting a new one

> pushing for a broken state resolution algorithm (decentralized consensus) without a formal analysis, which means it's now reached its 5th or 6th version and Matrix

In fact there are 9 versions today. Though afaik only one of them was due to a broken consensus algorithm. Others exist for new features. Strangely I can use even the latest ones with alternative clients such as Fluffy Chat - contrary to your claims

> but why is a Jitsi <iframe> considered a decent extension mechanism

It is? Source needed

Native Matrix video chat is being implemented as of now

> putting all of their $$$$ into a single web client with very bad performance, not caring for other platforms

Also wrong: Element has a native Android and a native iOS clie t