Pretty much every PR does get reviewed before merging (especially of non-committers) and compromises would be easy to detect in the typical version bump PR. At

Pretty much every PR does get reviewed before merging (especially of non-committers) and compromises would be easy to detect in the typical version bump PR. At least it's all out in the open in a big monorepo. E.g. in Debian, maintainers could push binaries directly to the archive a few years ago (I think this is still true for non-main) and IIRC even for source packages people upload them with little oversight and they are not all in open version control. Of course, Debian developers/maintainers are vetted more. But an intentional compromise in nixpkgs would be much more visible than in Debian, NPM, PyPI or crates.io.