You own the hardware, which means you have the ability to boot the system into diagnostic or repair modes for extended privileges. This doesn't mean that during

You own the hardware, which means you have the ability to boot the system into diagnostic or repair modes for extended privileges. This doesn't mean that during normal operation there should be a superuser account with 100% access. Plan9 from Bell Labs pioneered (edit: they probably weren't the first, but it's the first OS I can think of that does this pervasively -- I bet mainframe systems are similar but that ain't my cup of tea) the idea back in the 90s, where certain processes (like the credential store factotum) were sealed off even from the root equivalent. If you had physical access, you could add a flag at boot to enable access to these services, but this was not enabled by default, which is good.