FaceTime? That's probably the closest to what you're looking for. It's end-to-end encrypted, runs on (Apple) phones and computers (which is its biggest weakness for this use-case), does not require joining a "community", and is dead-easy to use. Signal is also great and doesn't require an iPhone, although you have to convince everyone to install the app.

Everything in this space is a trade-off, unfortunately. To my knowledge, there's no open-source, end-to-end encrypted, decentralized, peer-to-peer, mobile-friendly, and easy-to-use audio/video calling platform.

Assuming that the solution is end-to-end encrypted, I'm not too worried about it being OSS or P2P. For non-technical friends and family, the mobile-friendly part is far more important. Even mobile-only is probably fine for this particular purpose.

I personally prefer Telegram. It's voice call quality (as well as everything else it offers) feels perfect (your mileage may vary - obviously this depends on your location, your ISP etc) and the bandwidth consumption is shockingly humble. It can also let you send voice messages and video messages easily. Video calling is not there, however - it's a feature planned to be shipped later this year.

Let me mention there is an entire StackExchange site for this kind of questions: https://softwarerecs.stackexchange.com/

You should have posted the question there and submitted a link to it here on HN.

Thank you for making my question more palatable for HN readers! Really very much appreciated. You just made me realise I need to practice my HN question asking skills :)

Thank you.

It's not worked, though, since no one is replying. A lot depends on luck as to whether something gets noticed, up-voted, and replies.

I might try re-posting tomorrow morning (my time) in an attempt to catch a different audience. Then if there are still no replies, I've found a good time to ask these sorts of questions is on a Saturday at about 10:00 UTC.

And good luck, I hope you get the information you're looking for. The answer[0] from maverick74[1] might also be useful for you, but you've probably seen that.

Cheers.

[0] https://news.ycombinator.com/item?id=23526270

[1] https://news.ycombinator.com/user?id=maverick74

Jitsi is open source, easy to use (click shared link) and secure.

I once used Jitsi (the browser-based version) and my CPU usage went above the roof (even after I've disabled HD). It felt like my MacBook Air was going to blow up. Obviously not a battery-friendly app. I still feel like I'm going to use it again when I need a video conference - just for sake of using self-hosted free software.

Not a perfect match, but we use zoom.