Docker eases the automated setup.
Yours surely does work but docker compose is really nice if you want to have multiple types of one thing on the same hardware (like 2 sonarr/radarr for 4K content).
Simply impossible with regular installs.
Also while yes it complicates somethings it also makes maintenance so easy with updates than anything else.
Remove the image and you are only left with files you put in /path/to/folder.
Remove a conventional program and you’d need to hunt down the files it created somewhere in the file structures like AppData or /opt and other folders.