That is not what I said. I never claimed that rsyslogd cannot cause corruption. I just claimed that there are not-so-rare cases where rsyslogd and alternatives work, while systemd causes corruption.
If that's what you said I'm afraid it wasn't obvious to me. I took "Systemd causes log corruption where sane alternatives do not have such issues" at face value.
In addition, the corruption by rsyslogd is usually what you describe, namely things cut short. With the binary log-format from systemd, the damage is far more extensive, so, yes, rotating them is "right", but having binary logs is deeply wrong in the first place.
I don't know anything about journald's format, but if it suffers 'extensive' damage under challenging conditions that syslog handles fine then it's not an appropriate binary format for this job. That's not a fault of binary (which can be as robust as you want), that's a fault of the wrong kind of binary.