No this false. We don’t configure using bash. We configure by atomically swapping a symlink or mountpoint. One operation. Implemented in rust these days. You can run a Nixos system without any bash. We even have a profile for that. Bash is only mandatory during build time
all linux distros are just piles of bash scripts
except for nixos, which is configured using an advanced lazy functional programming language...
...which evaluates to a pile of bash scripts