Adding onto what’s already on the thread, you can try look at the newer Element Call, which is an implementation of Matrix’s native calls.
I’ve been using it a bit recently, since Jitsi seems to have stopped working reliably for me (to be frank, I’ve not put much effort into debugging it yet). It works well, but it’s still early stage, lacking some features Jitsi has. If that one works for you, I recommend you stick to it.

It’s tangential, but Mumble is still good for voice only chat. Rarely do we find video to be useful or necessary with a lot of collaborative tools showing multiple cursors per users & programs like Upterm that allow sharing a terminal session.

If I remember correctly, Jitsi is not E2EE by default. You need to set it up manually.

Jami on the other hand, is E2EE by default and decentralized (if I’m not mistaken).

Jitsi was a pain for me to get working the way I needed it, but I have to say I’m a fan so far. I haven’t used it too much yet (mainly just testing with myself from various networks/devices), but from what I can tell it’ll work for my use (replacing Google Meet for my family chat uses).

You’re probably going to end up on Jitsi meet, but I’m also going to drop a recommendation for bigbluebutton.

I recently noticed that it was integrated into the open source Learning-Management-System Canvas, which every school I have gone to so far uses.

Although bigbluebutton doesn’t seem to explicitly support e2ee (but maybe this counts for something), if you are already using Canvas, BigBlueButton definitely worth looking at.

I really, really wish people at my school would use the integrated bigbluebutton instead of using zoom, especially given I’ve seen people occasionally have issues with authentication for zoom, but all of that stuff is handled with bigbluebutton because it’s fully browser based and integrated into Canvas.

Jitsi, Nextcloud Talk and Signal are all very good options (if you don’t need screenshare with desktop sound (e.g. a watching a tutorial video with sound), I haven’t found a FOSS solution that can do that - though tbh it’s been a while since I tried it with something other than Signal)

It’s already been mentioned, but I’ll throw in for Jitsi. I believe it can also be self-hosted.

never heard of jitsi, but looks pretty legit from what you shared!

Jami is also an option

Maybe Signal since they have group call links now ?

We used Jitsi quite a bit during Covid, I was very happy with it, and I don’t remember any complaints from other people.

I personally haven’t used it yet but I believe you can do all this with Matrix (choose your client - probably Element).