The upside of Nix config is that it's the state of my system in a declarative config file.

I have these packages installed and these firewall settings and these users with these permissions and this folder served over Samba and these hotkeys that do these things and these Obsidian vaults synced over SyncThing and these devices in my SyncThing network and Neovim installed with these plugins and ...

This is difference between me and a non-nix user, not whether we can rattle off the exact state of our live system from memory.

The non-nix user has to query live system state, if such query tools even exist for their question, and I get to read a config file. And I get to maintain my system config in git, and I get to deploy my config on all of my machines.