Originally it was for the Pi, but can also be installed on x64 PC systems, either UEFI or BIOS, so basically runs on anything. It does run great on a Pi, it’s biggest advantage being that it logs to RAM, which massively saves on SD card wear. It’s also the only current distro which works reliably on the original Pi 1 nowadays (if you still have those hanging around!)
And I get that everyone saying “Docker!” is a bit boring, but there is a reason for it - containerising everything does make it a lot easier to manage and migrate everything to another system or revert back a single component to a different version. And you just backup a config file and your data folder for each container and you can recreate your system so easily. If you install directly, you have to worry about databases, file paths, permissions… but as you said, there’s nothing wrong with just installing stuff. Especially if it’s only a few programs.
I run 26 docker containers. Installing all those on a system would be a mess…
The biggest advantage for docker in the “home lab” environment is to be able to try out an app, but if you decide you don’t like it, removal is simply deleting the container and the data folder. That’s it. No trace left.
Sadly you can’t say that for installed apps.
But I agree, if it ain’t broke, don’t fix it. Seems DietPi will be right up your street and look after things exactly how you want, simply 😁