I mean they sort of serve different purposes. You can build a NixOS ISO running your exact desired configuration that is good to go immediately upon install. Ansible would require post install configuration, yes it is scripted but it is additional overhead and time. I think a better alternative would be an OCI based distro with a Packer build pipeline, which could include Ansible steps higher up in the build process. But that’s more complexity that Nix wouldn’t require

Prometheus, grafana, loki

Peertube is the fediverse alternative. It’s cool but not a ton of traction right now

I don’t care much for proxmox but that’s because I live in the terminal anyway and have a lot of experience administering Linux systems. So for me it’s just an extra layer of complexity, the benefits don’t really apply when my setup has IaC, most of my containers are in Podman rather than LXCs, my backups are automated with my own scripts and cronjobs, and I only run a couple of VMs. Also it makes encrypting the base system more difficult than it is with a standard distro

For todo I use my Radicale instance and Tasks.org as my mobile client. It’s all treated as CalDAV which I was already using so it’s convenient