Is it better than Jitsi?

I personally see Matrix bring the all-encompassing solution for secure and independent communication.

This seems more like a Zoom competitor with the features enumerated.

The wording is a bit clunky, as the native language of the website is German, but they offer this English translation of their tech stack:

"Rust is a modern programming language that we use to interconnect our OpenTalk backend team. Fast, secure, and efficient - ideal for the development of a snappy video conferencing solution with massive scale-out. Our backend team members love working with Rust and will never go back to anything less capable.

Our frontend uses JavaScript/React and Redux, focused on security and performance."

https://opentalk.eu/en/community

Later than expected, but now it's available under EUPL 1.2.

While I'm a European I would prefer it would be under an OSI or FSF approved license.

EUPL is approved by the OSI and the FSF

You are right, I stand corrected.