It does seem to be much less common, but the home directory based nix install is extremely useful if you don't actually have admin rights on the machine. I.e. in basically any institutional system. I have a very handy nix install in my home directory on a university supercomputing cluster. As annoying as it is to have to compile everything it's much better than not having that software at all or having to go though the sys admins to maybe get something installed a month later.