macos – ‘sudo’ is missing on recovery terminal

on my MacBook, I booted to RECOVERY TERMINAL.

I get this error “sudo command not found”

critical commands like sudo, brew, su and others are missing from

i searched with
ls -la /usr/bin | grep sudo

Can a bad actor with physical access to my machine delete these from machine? (No Firmware Password Set)

how do I install them back?

When I boot my MacBook with my regular username, sudo and everything else works.

How do I make sure the system recovery software, boot loader and its components are updated.

P.S: I have upgraded to MacOS BigSur