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.
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".