Why does cgconfigparser fails to mount cgroup with error as “permission denied“ when invoked by systemd?

Issue

• Why does cgconfigparser fails to mount cgroup with error as “permission denied“ when invoked by systemd?

# systemctl status cgconfig
● cgconfig.service - Control Group configuration service
   Loaded: loaded (/usr/lib/systemd/system/cgconfig.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Fri 2022-02-18 08:55:14 IST; 4s ago
  Process: 1857 ExecStart=/usr/sbin/cgconfigparser -l /etc/cgconfig.conf -L /etc/cgconfig.d -s 1664 (code=exited, status=101)
 Main PID: 1857 (code=exited, status=101)

Feb 18 08:55:14 localhost.localdomain systemd[1]: Starting Control Group configuration service...
Feb 18 08:55:14 localhost.localdomain cgconfigparser[1857]: /usr/sbin/cgconfigparser; error loading /etc/cgconfig.conf: Cgroup mounting failed   <=---
Feb 18 08:55:14 localhost.localdomain cgconfigparser[1857]: Error: cannot mount cpuset to /mnt/cgroup/cpuset: Permission denied   <=----
Feb 18 08:55:14 localhost.localdomain systemd[1]: cgconfig.service: main process exited, code=exited, status=101/n/a
Feb 18 08:55:14 localhost.localdomain systemd[1]: Failed to start Control Group configuration service.
Feb 18 08:55:14 localhost.localdomain systemd[1]: Unit cgconfig.service entered failed state.
Feb 18 08:55:14 localhost.localdomain systemd[1]: cgconfig.service failed.