nix-ld is a link loader. It isn’t a universal ‘let me forget that I’m running on a non-standard Linux distribution’ tool. It could, theoretically, be one component of such a tool.
The best all-in ‘forget I’m on NixOS’ tool that currently exists, IMO, is distrobox. But if you regularly find yourself wanting to disengage from the constraints of NixOS, you should consider installing Nix on a distro that isn’t NixOS. You can still get, e.g., declarative configuration of services by running NixOS containers for those services. I did this for many years.