I agree the way Brendan Eich was treated is a disgrace, and Mozilla's governance and misplaced priorities are at the root of its increasing irrelevance.
Not Matrix because I've been running XMPP since it was a thing, also because it is a standard which works everywhere. I'm not opposed to Matrix but XMPP+OMEMO do quite well for now so I have not had a reason to jump ship. If I feel that need Matrix is one of the options, as is something like Delta Chat which uses SMTP and as such interacts with everyone and his dog without the need to convince them to install some app or open an account on some site.
I agree the way Brendan Eich was treated is a disgrace, and Mozilla's governance and misplaced priorities are at the root of its increasing irrelevance.