It's not just the syntax (for me anyway). I just don't care about the how the derivation composes in practice, how it does overrides, how it integrates with flakes, how it applies the best-practices-of-the-day. I see the derivation as pure function as a cool theoretical exercise - but not something I want to actually write.
I want to actually declaratively say: here's an autotools package with some parameters I defined, give me the fancy overridable pure nix equivalent.
It sounds like https://github.com/jonringer/nix-template might be helpful to you. You can generate a nix expression to build an autotools package, and you can even pull the package info straight from a public repo. In the case of nix, most C-type things fall under stdenv, so that is the template you would want to use.
I barely write any C, but I've gotten very good at building C/C++ applications over the past couple of weeks by fixing broken derivations ahead of a release.
I want to actually declaratively say: here's an autotools package with some parameters I defined, give me the fancy overridable pure nix equivalent.