I wrote my own program, filetailor. It's similar to Chezmoi but uses inline comments instead of templates for machine-specific lines. This allows me to make edits directly to my local files and then sync those changes to other machines.
I also use Ansible.
I agree and use Arch as well, but of course I wouldn't recommend it for everyone. For me, having the same distribution on both server and desktop makes it easier to maintain. I run almost everything using containers on the server and install minimal packages, minimizing my upgrade risk. I haven't had an issue yet, but if I did I have btrfs snapshots and backups to resolve.