A lot of the replacements are just a "services.grafana.enable = true;" or similar away. Of course, won't have fancy GUIs like in TrueNAS, but honestly, being able to keep it as source code feels better long-term. Otherwise it's all just configuration, like background scrubbing, backups and all that. The biggest reason I initially went with TrueNAS was because it used ZFS and could easily run services I wanna host at home, and NixOS ended up much better at both of those things, but definitively has less hand-holding.