I'm planning to use my Pi for a few small services and nothing else. Currently it has my VPN and apcupsd installed directly, and I want to add Grafana, Prometheus and Uptime Kuma to it.
I was going to install Docker to use the last three, but ultimately, is it really needed? I won't be using the system for anything other than these purposes, and I just plan to set them up then almost never touch it again. Once it's set up I'm cloning the SD card too, so I don't need the centralized folder structure of Docker either.
And I'm already using Docker pretty heavilly on another server, so I don't need another environment to learn on either.

So with all that, is it worth installing Docker on my Pi to run these services? Or should I save a small amount of storage and processing power by just installing them direct to the system?