> ...at it's core systemd is just a glorified script runner as well?

Yep. And it has a ton of accidental complexity in it. [0] At $DAYJOB, we ran into a production-down incident related to inscrutable SystemD failures once a year. It was always the case that the documentation indicated that our configuration and usage was A-OK. If there ever was a bug report filed, it was always the case that the SystemD maintainers either said words to the effect of "Despite the fact that the docs say that should work, that's an unsupported use case." or "Wow. Weird. Yeah, I guess that behavior is wrong, and it's true that the docs don't warn you about that.", and then go on to do nothing.

SystemD is -IME- like (again, IME) PulseAudio and NetworkManager... it's really great until you hit a show-stopping bug, and then you're just turbofucked because the folks who built and maintain it it want to treat it like it's a black box that works perfectly.

[0] NOTE: I am absolutely not opposed to complex things. I'm opposed to needlessly complex things, and very much opposed to things whose accidental complexity causes production issues, and the system's maintainers' reply to the bug report and minimal repro is "Wow, that's weird. I don't want to fix that. Maybe we should document that that doesn't work." and then go on to do absolutely nothing.