Some of you have probably seen the blog post a few months ago about how GNOME is more strongly depending on systemd. The changes mentioned there have landed into the latest stable versions of the mentioned software (GNOME 49) and do affect us. In particular, the main culprit is the removal of the non-systemd fallback code in gnome-session. This makes it currently impossible to launch gnome-shell/mutter on a non-systemd system. A fairly straightforward patch of using elogind, like what was previously done, no longer works either.
Since we don’t have the time or interest to write a new non-systemd codepath for gnome-session, this means that all support for gnome-based desktops has to be dropped. In particular, the affected packages would be gnome-session, gnome-shell, mutter, and gnome-settings-daemon. For now, the old versions are still in the repos but because there is so much intertwining between other gtk/gnome packages, there is no guarantee they actually work and will later be removed from our repos.
Standalone gnome applications will still continue to be packaged, but it is simply not feasible anymore to support gnome desktops without systemd.
No. It doesn’t support BSD, just for starters, even though most of the established desktop environments originally ran there as well as on Linux. So by definition, anything that relies on systemd can’t “support as many systems and platforms as possible”. And to my knowledge, no actual standards document defining protocols and interfaces has ever been published (although I admit, as an OpenRC user, I don’t pay much attention), meaning that the interface can change without warning. If systemd works for you, that’s fine, but don’t try to build it up into something it isn’t.