[Elhana]

That is the point - you often can't just recompile journald part, because it is tied to systemd interfaces and you might not be able to easily upgrade systemd, because it is a production system you can't simply reboot like your home server. The only way to do that is backporting specific patches to the older version.

If it were a separate component, it would have a bunch of ifdefs covering several versions of systemd, possibly with some features disabled if older version doesn't support it. However, that somewhat increases code complexity for developers and systemd devs refuse to do that.

That is the point of 'monolithic' criticism - despite being many binaries, you can't easily just build single one and make that work.