For private meetings with video/audio, the real choice remains open source software: Jitsi, @nextcloud Riot/Matrix, Wire, Signal. For groups, Wire seems to be the only end-to-end encrypted option, so using a trusted service provider is essential. You can find a list Jitsi instances here: https://github.com/jitsi/jitsi-meet/wiki/Jitsi-Meet-Instances
@ajz @guardianproject @nextcloud #Signal is *not* a #privacy-respecting option: https://github.com/privacytoolsIO/privacytools.io/issues/779