Just wanted to bump this thread with new video call software I've discovered, free, open-source, called Ring.
https://ring.cx/en
Its available for Mac, Windows, Android, Linux. It doesn't need an account on a remote server. Its completely decentralized. You make a password, it generates a key. You give this key to whoever you want to video call, and you're video calling seconds later.
On Linux, my platform of choice, things like video calls can be difficult and frustrating to actually get to function, even using software that's supposed to make it easy. With Ring, I've never seen something like this just work perfectly right out of the box, seconds after an install. Perfectly clear audio. Perfectly clear video. No dropouts.
So if they've aced something like this on Linux, I can only imagine it works as good or better on other platforms.