Why is systemd attempting to handle X,Y and Z that are unrelated to it's function
Simple answer is that unix was not designed for people who are ignorant and disintested in their OS. It was designed for people who had taken the time to learn the basics rather than assume the OS knows what it is doing because they don't want to.
Microsoft took over computing for the last forty years because they sold it as ignoramous compatable, no intelligence or understanding required and systemd is an attempt at catering to the same "why won't it just work by itself" crowd via the same halfassed method of ignoring the implications with default answers.
Yes unix can be configured so the ignorant user can safely do their browsing etc but when the user also demands root then you have the same outcome as giving matches to children.
We can either give the kiddies matches and let the world burn or restrict the important decisions to people willing to learn and accept the implications. Systemd doesn't do either and should never have been allowed to gain the prestige implicit in being a dependancy nor allowed to replace working components with fudge just to make their failed design appear to work.