Voice and video with non-technical friends and family

I'd like to get friends and family off Facebook, but one of the things they use it for is calling people, both voice and video.

So I'm looking for a replacement. Ideally whatever we use would run on both phones and laptops/desktops, preferably with a light-weight client. We would need audio, video, and screen-sharing would be useful. Ideally it would be P2P, and not controlled by a single entity.

Privacy is a concern as a general principle, and I'd like to be able to avoid joining another "community".

My betting is that such a thing doesn't exist, but I'd be interested to know what trade-offs people think are available and accessible for non-technical people. Matrix was one option, but I've heard that some people find it difficult to impossible to get audio and video working. Another option might be Tox, so I'd be interested in hearing of people's experience with that.

But all comments, suggestions, and thoughts welcome. Thanks.