> My point is that if you care deeply about what is being installed in the image, size, dependencies, bloat, etc. then perhaps using the NixOS abstraction is the wrong approach. Instead of building "down" by taking things away, build "up"

Those aren't necessarily oppposing points.

NixOS is a declarative distro. It also happens to come with some defaults that, I assume, caters to the commonly expected use case (and maybe has some historical roots as well).

NixOS is not a minimal, build-from-scratch distro. It's more opinionated than e.g. Arch. For example, it ships with firewall turned on by default (https://nixos.wiki/wiki/Firewall). Another example: the default list of packages is somehow Perl, rsync, and strace (https://search.nixos.org/options?channel=26.05&query=default...). Blanking this default to an empty list is IME harmless.

The declarative nature is probably the subtext the author is trying to convey: what are the things one can do to disable these defaults, to reach a very minimal system (ISO really) that one can then build as one wishes.