I would love to see a discussion from somebody who really likes Nix on why it isn't ready for prime time yet/just play devil's advocate aloud on why it isn't the greatest thing since sliced bread.

I feel like I must not be doing anything "serious" enough to need package reproducibility at that high level. I'm aware of things like git checkout/tags, package-lock.json, Cargo.lock, Docker image tags.

What is a real world use case where Nix isn't overkill? I've read toolchains but... nvm (node version manager), rustup. I still Rust on a machine once and I never think about it again.

It feels like the Kubernetes of package management/build if you will complexity wise. "Do we really need this or is it just what everybody else is doing?"