Is su on ground unit possible?

as I’m trying to mod routing table ( or just doing a traceroute ) on ground unit I need to get superuser acces but when trying to get su I end up with

$ /bin/busybox su root                                                                            
su: must be suid to work properly
$ cp /bin/busybox /tmp/
$ chmod u+s /tmp/busybox 
$  ls -l /tmp/busybox                                                                         
-rwsr-xr-x 1 shell shell 1916896 2021-09-27 15:34 /tmp/busybox
$ /tmp/busybox su                                                                             
su: must be suid to work properly
$ /tmp/busybox su root                                                                      
su: must be suid to work properly

I’m a bit confuse is there any root user on ground unit ?