Previous job was using self-hosted Jitsi. And it was often a trainwreck, with random disconnections, terrible video quality (and we didn’t use it very often), some people ~always displaying "connection lost" even though we could hear each other fine, some people always having connection issues and being disconnected after a few seconds. Zoom and Teams are much more stable.

Main downsides I knw of are a slightly worse codec, and in webrtc mode bandwidth needs to scale with participants so for large meetings you need to pay for hosting somehow.

Neither are reasons not to use it as a default first option.

Also matrix has voice and video now and there's big blue button.

I've never used voice in Matrix, but I was sure that it was implemented using Jitsi on the backend?

Element had a jitsi plugin i think. the matrix voice/video is new and i only used it once

My aunt that do remote conference a lot told me jitsi is slow and ureliable? She's not very tech savy so maybe she had a bad experience at the time when lockdown happen and the servers might have been overloaded.