Earlier quoted context omitted.
systemd is so complex, I've come to a conclusion, that it no longer fits my definition of free software. We allow runaway complexity to obscure the inner workings of an important software package, to the point, where having source access no longer makes a practical difference to a "casual" power-user or even a software engineer. I can source-dive runit, s6, OpenBSD's rc, or OpenRC and within a weekend, have a pretty…
Have you actually tried to dive into the part you're interested in? Where did you find the complexity? I've done it a few times for different components and found them pretty well separated and the source pretty straightforward. I have other issues with them, but complexity/obscurity of the is was not one of them.
Boot Loader Interface, Discoverable Partitions Specification, etc.
I’m sure the implementation details are very interesting.
But where is the “Configure and Start a Service” option? Which is arguably the most important.