Sudo apt… is not the problem. Home-manager and a list of packages are so much better and easier to manage. That’s why I’m currently running nix on top of Debian.
The problems start when you want to modify something, or when you want to use tools that expect fhs complience. Then you run into a skill mountain and discover that the documentation is not great.
At least that’s my experience with guixos and nix. I haven’t tried nixos, and if I do, it’ll be only to generate docker images and such.
For a workstation, in most cases, there are simply not enough benefits to deal with the bs that comes with a declarative os.