Yes. (Docs at https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3....) Although it won't "throw it away" in the sense of uninstalling it; it's just that when you exit the shell, you'll be back in an environment which doesn't have the symlink to `ranger` on the PATH.
It basically garbage collects it (you can run it through a periodic service, or call it manually). You also have older versions intact, so you can simply change back to a previous version instantly.
Also, this is the only package manager where I could reliably install gnome and plasma, and have it removed to the last package - pacman and everything else will leave behind random files all around the place.
Well, it can’t help random spamming, but home-manager actually can help here! You can have a declarative config for your home dir and it will symlink config files into your .config folder. Also, it will by default never overwrite any file, but it will ask you to remove spammed configs over which you want to use your own, and since these are symlinks, they are read-only so no program will change them (which is good and bad, because it means programs can’t be configured through their gui settings for example)
it's really useful if you work on projects that need different version of dependencies, as you can define on a folder basis what jdk or python versions you want to have. You can even commit this to git so that everyone has the same env locally
For non-nix usage, I use a docker container with debian in such cases. Just docker run, apt install, keep using while needed, then stop and rm the container. Works great to keep the main OS clean.
