[Conscat]

It does not in the general case. For KDE, it works for some programs, but not all of the common ones including Discord.

[patrakov]

There is a project to fix this.

https://blog.davidedmundson.co.uk/blog/xwaylandvideobridge/

https://invent.kde.org/system/xwaylandvideobridge

[vetinari]

It does work for programs that use pipewire portal.

It doesn't work those, that call XGetImage on X11 root window and think, that they will get away with it.