Why does the RHEL 8 system boot into emergency mode with `Failed to switch root` error ?

Issue

• During boot system goes to Emergency mode with Failed to switch root error. Observing below error in the rdsosreport.txt file :

  localhost systemd[1]: Starting Switch Root...
  localhost systemctl[1027]: Failed to switch root: Specified switch root path '/sysroot' does not seem to be an OS tree. os-release file is missing.
  localhost systemd[1]: initrd-switch-root.service: Main process exited, code=exited, status=1/FAILURE
  localhost systemd[1]: initrd-switch-root.service: Failed with result 'exit-code'.
  localhost systemd[1]: Failed to start Switch Root.
  

• The root file system is not showing under /sysroot in the Emergency mode.

  # mount -o remount,rw /sysroot
  # ls 
  /var/lib/nfs/rpc_pipefs