I am exactly in the same situation as you (I did not know frigate, but I do not have cameras either - otherwise you listed my main systems).

I managed to reduce administration to a minimum by using watchtower to automatically upgrade my containers and using mostly the :latest label.

This bit me only twice in a few years:

- with the 19-20 migration of Nextcloud, I had one big blank screen when logging in but the synchronization was working. Turns out it was a new default app (something about dashboarding) that was causing it. Googling an fixing took an hour.

- with one upgrade of Home Assistant where my devices were not available anymore, there was a problem with the upgrade which they fixed quickly but I have already upgraded. Reading the docs/forum and fixing took an hour.

I can live with these two hours across two or three years.

I backup /etc on my server with Borg and I know that, worst case, I will recover. I tested this DRP two weeks ago bare metal (recovering to an empty VM from scratch, that is an ubuntu ISO and ultimately getting my encrypted backups from a friend's system -> it really helped to highlight what I was missing)