Zoom already does 256bit AES end-to-end encryption. From what I understand it isn't the live calls but the files and recorded calls you save on their servers after are what they would use for AI training.

Zoom already updated their TOS a few hours ago to supposedly address the issue. https://gizmodo.com/zoom-ai-privacy-policy-train-on-your-data-1850712655

Update, August 7, 5:06 p.m.: After this story was published, Zoom issued an update to its Terms of Service. The article has been updated to reflect the change.

If those you wish to have a video call with already have each others phone numbers then Signal is a option. It supports up to 40 participants. Available on Android, iPhone, Windows, Mac and Linux.

Signal has other great chat/messaging features too.
Also a unofficial community on Kbin

Zoom and MS Teams both seem to have E2E encryption for 1-on-1 calls. They own the code, tho, so whether they really cannot decrypt the stuff is a matter of trust.

Yes. End to end encryption between two parties is pretty trivial to implement. Video and audio is no exception.

I'm not sure about the technicals, but there are some services that are HIPAA compliant, which I assume means something similar to the end-to-end encryption you're describing. WebeX is the one I know one of my local hospital systems uses.

Yes, E2EE video call software exists, but then you’d be using something other than Zoom.

Theoretically you could have everyone in a call use a plugin that “added” E2EE to Zoom, but I’m not certain such a plugin exists - and even if it did, ensuring everyone you communicate with Zoom uses it would be enough of a barrier that it’d be simpler to just use something other than Zoom that has E2EE baked in.