These are good points, but one reason to use Ansible to configure NixOS is if you must continue using Ansible to configure other computers / cloud instances tha

These are good points, but one reason to use Ansible to configure NixOS is if you must continue using Ansible to configure other computers / cloud instances that are not running NixOS. It would be easier to adopt NixOS if you could do it incrementally rather than replacing everything. I suppose one could use Nix to configure computers that are not running NixOS? Switching all of my Ansible playbooks to the Nix package manager is non-trivial, but perhaps less effort than changing every OS at the same time? But can you use Nix to interact with the cloud? I currently use Ansible to spin up virtual servers on Linode using their web API, for example, and I expect to have to interact with AWS or Google Cloud in the near future.