My favorite quote is: containers and k8s are perfect for shipping poorly architected software that was built to yolo the dependencies and the os configuration it runs on.

In the real world you're going to need to understand what your dependencies are (if only for understanding and closing security holes when they are discovered) and you will be in a world of pain when the yolo approach catches up with you.

I'm not saying to not use containers btw. I think containers are great and can save time when use properly. They are just not the panacea people make them out to be.

With nix, you can't precisely specify versions of all your tooling. You have to choose a channel, and you get whatever that channel gives you. You can't upgrade one tool without upgrading everything else at the same time to whatever version the channel provides. For many dev workflows, that's not enough control.

See https://github.com/NixOS/nixpkgs/issues/93327 (which grew from https://github.com/NixOS/nixpkgs/issues/9682)