Another pretty great thing with Zoom is that it'll keep a call up even if, say, your home internet drops out and you switch to tethering on your phone. It sounds rare, but with Australian internet or dodgy campus wifi, this is a really useful feature.
No, you've missed the point - you don't quit and rejoin, it just freaking stays up. It's really remarkable - I can switch networks and VPNs on my macbook any time during a screensharing session and get nothing more than a slight delay for a second on video, and zero perceptible drop on audio.
It's also very good at handling connection slowdowns. It will drop video first, while audio keeps flowing. If someone loses their connection altogether, it buffers their voice, and plays it back slightly faster to catch up (sounds weird, but it really works).
I'm not sure about remarkable, it's a quality of implementation issue. Around the turn of the century I worked on an EU project where we did this for voice calls with IPv6.
In the present era QUIC can support doing this, although whether that'll be something every popular implementation actually does remains to be seen, but again a high quality implementation will be able to just rebind - "Hi, this is still me, I just have a different network address now" and carry on seamlessly.
