IMO, NixOS is like arch but it forces you to declare everything up front.
I’ve seen people create advanced configs with Arch then bring them over to the locked-in world of NixOS. I’d add that Home-Manager is crucial if you decide to do that (less so if you are building headless machines or VM’s). Ps. You can even build a super customized config then run it as a NixVM in your favorite container manager/k8s cluster.
Insane even.