This is trivial to do on NixOS:

  services.xserver.videoDrivers = [ "nvidia" ];

For a full install for eg machine learning, you'd want these lines, too:

  environment.systemPackages = with pkgs; [
    cudatoolkit
  ];

  systemd.services.nvidia-control-devices = {
    wantedBy = [ "multi-user.target" ];
    serviceConfig.ExecStart = "${pkgs.linuxPackages.nvidia_x11}/bin/nvidia-smi";
  };

You can download blob from official site, but it wouldn't work in a lot of cases after installation process while giving you no options for some choices there are (like GLX provider or vendor-neutral OpenGL libs), that's the difference of Debian's metapackage.

(you do need to set config.allowUnfree = true; or the nvidia stuff will be hidden)

Pop_OS! By System76 makes these accessible at the installer. It's why I chose it for a recent Lenovo laptop purchase.

So now you know of 2.

As Ubuntu does on theirs. The thing is, Ubuntu is stated as officially supported by Nvidia's blob itself, although it doesn't remove all the fun of their driver's installation and configuration processes.

Yeah I only mention pop_os because it truly is a painless process for a fresh install and that's worth calling out. Life is too short to suffer installing uncooperative Linux distros on modern laptops.

Pop_OS is based on Ubuntu, which is itself derived from Debian.

Pop_OS does not reuse Debian's packaging for this, does not do it the same way Ubuntu does. It also bundles it with the OS installer image, which can be pretty important.

These are decisions that OS authors make. Even if they are derivative, it is worth calling out these specifics. Especially if it enables painless adoption of the OS on specific hardware rather than saying "well it's just Debian."