I apologise ... you've caught me at a time when I'd love to help, but I personally don't have the specific knowledge you want. As a result the only way I can potentially help is to tease out from you your specific requirements s that others with more technical knowledge might be able to provide more in-depth information.
My point is that people will be frustrated if they suggest something only then for you to say you've already tried it and rejected it for reasons you haven't yet mentioned. That's why I'm trying to get you to be more complete about your particular context and circumstances.
I hope you don't mind, but I've re-written and submitted your question here:
https://news.ycombinator.com/item?id=23526263
Maybe that will get a response.
Meanwhile, let me explain more ... this will sound brusque, but when I'm in "technical" mode I tend to deal with what's in front of me, and not wrap it in "soft language". Being in "Manager Mode" is possible for me, but an effort, and incompatible with the technical work I'm buried in at the moment.
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> Well, I asked a simple question on Matrix and Tox and you asked me to compare all the other chat applications under the roof.
No, you didn't ask about Matrix and Tox, you said:
> Which platform should I use to communicate with family back home?
You then said that Matrix isn't very friendly for non-tech people, and that you couldn't get voice or video chat working. Fair enough, that's why Matrix is no good for you.
Then you asked if anyone had used Tox. Fair enough, you've suggested something else. But your initial question remains:
> Which platform should I use to communicate with family back home?
So my training is to understand where someone's question is coming from before trying to answer it. I was asking about the limitations, the requirements, and then asking about what you've tried so people could get a sense of your experiences so far, and in what way they don't meet your needs. I could have just said: Why not use Facebook?
So now you've said:
> My requirements are simple: Lightweight client for both desktop and mobile; audio, video and screensharing; P2P; privacy focused and not controlled by single entity, does not limit features and does not force other communities onto the users by default.
Those are not simple requirements, and my bet is that nothing currently meets them.
I get the sense that you feel I'm being unreasonable in my replies, so I'll just finish by answering your original post "as is":
> Which platform should I use to communicate with family back home?
I don't know, it depends.
> Anyone used Tox?
I've never used Tox ... sorry.