I disagree. I don't use Nix, but I've been in situations before where an upgrade either couldn't complete, or catastrophically broke something. Those situations

I disagree. I don't use Nix, but I've been in situations before where an upgrade either couldn't complete, or catastrophically broke something. Those situations are horrible and can take hours or days to resolve. Having the option to say "fuck it" and just reinstall everything, without worrying about manually installing exact software versions and reconfiguring everything sounds amazing.