XMPP allows for various different client styles while Matrix doesnโt
Fully featured, mature text-only clients for XMPP exist, but for Matrix there are only beta text clients available
Matrix handles/addresses are always public in chat rooms while XMPP chat rooms can be configured to hide them
Matrix has multi-server chatrooms for reliability in case of server or network issues while XMPP chatrooms alre always bound to one single server
Matrix Chatrooms can be encrypted. XMPP chatrooms can be encrypted or not encrypted. (thereโs no further explanation on this point, I assume itโs meant that Matrix servers can turn on encryption and thatโs it, while XMPP servers allow the chatroom administrator to decice and do not force one or another)
Administrative data is stored on one XMPP server. Matrix administrative data is stored on the servers of all connected users
XMPP is modular and the protocol itself can be extended while Matrix is monolithic
XMPP protocol uses XML while Matrix protocol uses JSON
Matrix focuses on reliability and availability of chatrooms, XMPP focuses on features and extensibility
XMPP uses less system resources than Matrix
Chatroom data storage is done only on the XMPP server the chatroom is running on, while Matrix stores chatroom data on all of the servers of the connected users
XMPP directly sends a message if the connection is open, otherwise a push notification is sent. Matrix only sends a push notification to the client and the client has to pull the message from the server
Organizational
XMPP is an IETF standard while Matrix isnโt
XMPP board and council are equally elected by all members. Matrix is a โsingle-party systemโ where the board decides who is allowed in the board.
For XMPP all members are allowed to question/check/validate the board and council and there are annual elections. For Matrix, the Matrix.org Foundation (technical council) and New Vector Ltd. (service provider) expect trust from the community.
On the XMPP board and council, all actors have to name their interests and their employer (this is to prevent having more than 15% of board/council members from the same company which would give a single company too much power). For Matrix there is no known information about such a clause.
Signal is probably your best bet for a solid user-friendly (and privacy respecting) experience with calls. Matrix/element is another decent option (its federated like lemmy and mastodon) but a bit less intuitive.
If you want a simpler solution than Matrix and don't mind using a non-opensource app you could try twinme. You only need a username and a picture to create an account (could be anything, "Jane Doe" and a white square if you want). It has a couple unique features like multiple identities and click-to-call links, which you can share with people who don't have the app so they can call you using only a web browser (e.g. on craigslist, lost pet flyers, ...).
I work on this app as a full-stack dev, and for what it's worth we only upload/store data that is strictly required for the app to work. We're lobbying to open source it because we have nothing to hide and we know how important it is for the privacy/security minded folks, but it will take some convincing before management agrees to it...
Thanks for checking us out :) We had an audit done by quarkslab a few years back, and another one coming up this year since we're currently implementing verified relations (signed SDPs). I'll edit my comment with a link when I get back to work next week.
I don't know why people are downvoting you, might have better luck in something like a technology-centered community or putting some more information like what device or uses you have for it.
If you're looking for an app for a mobile device while connected to wifi, there are a lot out there but they are all pretty sketchy in my experience (thinking like text-now which offers a free limited number to use but privacy and ad-blocking get thrown out the window). If you're looking for a messenger that doesn't have a number associated with it, something like matrix that was suggested should work (or whatever preference the people you communicate the most with prefer).
hmm, well it's unfortunately usually a "you pay for what you get". If you're not paying then you're gonna end up as the product. I only have experience with "text now" which I've used in a pinch before and it has some limitations on the calls which you'll usually end up running into on any app. I wouldn't be surprised if there was some better ones out there. If you're worried about what kind of App you're downloading you might try the !privacy@lemmy.ml community as someone there might have a better source that isn't constructed to mine your data.