My main problem with Matrix (which I'm willing to work around because of the benefits of a federated, self hosted, encrypted chat system) is that it seems to assume everyone has a lot of high end, modern hardware, at all ends of the system.
Synapse is fine until someone on the homeserver starts joining a bunch of rooms, then you'd better have a lot of RAM for it.
And Element, while a perfectly good client, is the standard "bloated electron app" option that chews 700MB of RAM and lags, entering text, on a Raspberry Pi 4.
There are alternatives, but they tend to have weird issues, at least last time I messed with them, in how they handle some of the corner cases of encryption.
I've used Matrix for the past couple of years for work chat system, and I personally think that the thing is a fad at best.
Synapse is simply awful as a server implementation, and the clients are just simply bloated.
But if you are looking for a good federated, self hosted, and encrypted chat solution, for my own private chat system; I've gone back to XMPP - I've settled on:
* ejabberd (which is in Erlang so just by definition is going to perform leagues better than Python) - prosody also works fine (especially for "lower end" servers) - though both need a bit of configuration at first install
I used Riot/Element since back when it was still called "Vector" (these guys love their name changes)
It's ok but it's really aiming at the whatsapp/telegram crowd. Open a few hundred channels and it's overwhelmed, especially visually. You can set the channels to a higher-density view but not the channel list itself. You're scrolling forever.
Unfortunately Matrix is very tightly coupled with Element, it's the only client that really implements everything.
I'd love something like Quassel (which is what I use for IRC now) for Matrix. Native app, excellent performance and features.
fwiw Synapse has got progressively better, especially in the last 6 months. Element performance has certainly got worse over time though and we are working on that now.
