As explained several times on this ML, depending against libsystemd0
package doesn't mean anything about requiring systemd to be used as
PID1 or not. Even Ian's GR was not taking the "I don't want any systemd
package on my machine" use case into account you know.
Why focus on PID1 ? As I said, systemd-resolved proved to be
vulnerable to a well known attack. What makes us think that more
quality was put in systemd-logind ? Not wanting systemd means not
wanting it *at all*. I personnally do not trust it for critical system
tasks.