We've used Skype, GoToMeeting, Slack... and finally Zoom, and Zoom was the best quality video conferencing by far. No echo, no sound+video synch issues, rarely

We've used Skype, GoToMeeting, Slack... and finally Zoom, and Zoom was the best quality video conferencing by far. No echo, no sound+video synch issues, rarely any "breaking up"... they must've implemented some very nice tricks to make all these work even when we have meetings with people sitting in from several different countries. Despite their security issues, it's not surprising they came to dominate the market: it was the only product that really worked.