Unfortunately still broken on gnome/wayland: https://bugzilla.gnome.org/show_bug.cgi?id=784199
edit: gnome bug not linux
edit: gnome bug not linux
Wayland has no screen recording API by default, so compositors implement their own - some already have their own, some, such as GNOME's mutter, don't.
But even if mutter implements it, that doesn't really fix it for all situations - there's many users on KDE, for example, for whom the GNOME bug is entirely irrelevant.
Linux != GNOME.
Thanks to the gnome-remote-desktop project, which landed in stable Fedora back in September.