From this point of view is systemd disaster because it is almost everywhere in the system - boot, network, logs, dns, user/home management…
That’s almost like complaining that GNU coreutils is a disaster from KISS point of view because it includes too many things in a single project - cat, grep, dd, chown, touch, sync, base64, date, env… Not quite, because coreutils is actually a single package unlike systemd.
The core systemd is big (IMHO it needs to be in order to provide good service management, and service management is a reasonable thing to include in systemd), but everything you listed are optional components. If your distro bundles them into one package, that’s on them.