For private purposes I occasionally do video conferences via Jitsi https://meet.jit.si/). Now I wanted to know whether it is possible to insert a virtual background or to make the background blurred. Do any of you know if and how this works? In Teams and Zoom, I can do it with a Win10 laptop.
In Jitsi you can currently only blur the background, unfortunately setting a different background is not (yet) possible.
Simply click on the three points at the bottom right and "Activate background sharpness (BETA)".
Jitsi works best in Chromium based browsers like Edge, Chrome, etc.
That Firefox doesn't work well (as has my experience) is unfortunately stupid. Will that get better soon or is it technically unrealistic for Firefox to manage it?
Yes I think so. At the beginning of the year Firefox didn't support the WebRTC protocol (which uses Jitsi) at all, so they are on the right track.