Ah....your Oracle software is not installed correctly. On my database:
[oracle@db20 bin]$ cd $ORACLE_HOME/bin
[oracle@db20 bin]$ ls -l | grep root
-rwxr-xr-x. 1 oracle oinstall 945 Jun 20 2016 acfsroot
-rwxr-xr-x. 1 oracle oinstall 1000 Jun 20 2016 afdroot
-rwsr-x---. 1 root oinstall 3080744 Mar 30 2020 extjob
-rwsr-x---. 1 root oinstall 2334824 Mar 30 2020 jssu
-rwxr-xr-x. 1 oracle oinstall 940 Jun 20 2016 okaroot
-rwxr-xr-x. 1 oracle oinstall 1007 Jun 20 2016 olfsroot
-rwxr-xr-x. 1 oracle oinstall 1616 Mar 4 2020 rootPreRequired.sh
Notice that some binaries are owned by root.
In your installation, I would suspect that someone did not run the "root.sh" script that is run after the software installation.