launchd has a clearly defined scope, and it restricts itself to doing only those tasks which fall under its remit.

If systemd had followed a similar philosophy, it would have been accepted without anything like the same amount of criticism. As it is, its scope creep is frankly absurd and dangerous.

Most of the additional functionality is optional, and in separate binaries. Apple also has similar functionality (seat management, resolver management, etc), and nobody is bothered by that.

One gets the impression that optionality is only theoretical. Same for separate binaries. The degree of coupling in the systemd architecture is enormous. So then, what purpose do separate binaries serve other than being able to (conveniently) be used for deflection or provide a certain facade?

The philosophy of systemd exemplified through PRAXIS is one of subsumption and uniformity (== taking away choice) under a singular vision defined by the systemd implementors. In practice, this means that you are penalized in various ways if you don't "buy in all the way". You can take a look at all the distributions that ship systemd by default and see how many have bought in all the way vs not using the "additional functionality".

> That systemd solves the problems that make it possible to react to events and makes laptop-usable distros possible?

It is one such solution. But there are others, which from an end-user perspective are much easier to deal with (e.g. runit, shepherd etc.).

So, for instance, my Void-powered laptop shuts down quickly and cleanly when I ask it to, and I don't have to wait 1:30 minutes (or more) on shutdown.

Launchd appears to actually work. And it isn't Poetteringware.