systemd depends so heavily on a files it can not reboot

[Richard Ryniker]

Sounds like an unfortunate situation that should be addressed by use of a
Live system, which can repair or salvage data from the afflicted file
systems.  If repair is possible, job done.  If not possible, solution is
to re-install the operating system.

Rather than invest serious effort to make systemd (or other components)
tolerate various types of severe damage to the operating system, it seems
better to learn how such damage happens, then devise ways to prevent this
occurrence in the first place.

If something is wrong, I much prefer to see an obvious symptom, even if
there is no clear indication of the nature of the failure.  I have too
often had to clean up damage when a "robust" application found some way
to continue, with unexpected semantics, after it decided it could
"tolerate" some failure.

Programs can be designed to detect certain failures and cope with them in
reasonable ways.  In your case with systemd, it is simply impossible to
continue in a responsible way without the configuration data systemd
requires, but lost when your file system was corrupted.