You're making an Apple to Orange comparison here. Your examples are not released to the outside world as a single product "take-it-or-leave-it" and painting it so is borderline bad faith.
Painting systemd in that way is also bad faith, because it's not a single product "take-it-or-leave-it" either. If you think it doesn't have enough review for your purposes then it's time for you to step up and start reviewing, either in systemd or in another project.
Part of the reason why people seem to (falsely) think systemd is monolithic is because distros have been historically bad at packaging it and haven't split up the components, but that's been improving over time.
Part of the reason why people seem to (falsely) think systemd is monolithic is because distros have been historically bad at packaging it and haven't split up the components, but that's been improving over time.