I think it would be great if such things were options, yes. Despite the common argument that systemd is actually modular, I haven't seen a lot of modular use of its pieces. In practice, use of systemd (and, again, I'm complaining more about distro devs than systemd devs) has seem to make things more inflexible (and brittle). E.g. Gnome Shell ended up with a practical dependency on systemd, though this has been successfully worked around. Snaps ("Snaps are universal Linux packages") are really 'universal systemd packages' (and in fact only 'universal Ubuntu packages' if you want sandboxing). But hopefully at some point it will be possible to more easily use the good bits of systemd without having to go 'whole hog' (so to speak).

The claim that systemd is modular is a brilliant marketing gag that rests entirely on how you define modular: software parts that are separated by clearly delineated interfaces can be called modules without being exchangeable. So in the eyes of the systemd guys the thing is perfectly modular, but as the users noticed, no part is exchangeable, which is what the other camp wants. And both camps get hung up over the contradictions without realizing that they need to redefine their nomenclature first.