For me the appeal of NixOS is that I never have to nuke my setup. I probably used to do that about three or four times a year when I was running a Debian variant. I'd get lazy and install a bunch of stuff globally with apt and pip and then not really know what state my machine was in, then nuke it and start afresh. With NixOS I know what state my machine is in all the time, can transfer the configs to another machine, and never have to nuke it. I don't know the Nix language, and haven't bothered to learn it. I do understand my own config files though and steal from others if I need to.