Okay. I have my config files set up to add /sbin and /usr/sbin to my PATH – that’s probably a config that dates back at least a decade – but it looks like Debian defaults to not having /usr/sbin or /sbin in PATH for non-root users; you can see this in /etc/profile, where it’s only adding /usr/local/sbin, /usr/sbin, and /sbin to root’s PATH, but not to other users.

If you run su -l, then that’ll give you a login shell as root, and that’ll have those in the path.

You can also add them to a regular user’s path. I don’t know what the “right way” to modify PATH for a graphical desktop is these days, so I can’t give much help there; with xdm starting Xorg, which is what I do, it’s to put it in a ~/.xession file, something like:

export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games"

and for login bash shells, like for if you ssh into the system or log in on the console, in ~/.bash_profile, the same.

But GNOME under Wayland and all those new desktop environments probably have some way to modify PATH, something which they run at when you log in, and I don’t know the appropriate place to stick those or which you use.