I have an 8 gig RPi4 (OS is Dietpi) with a 16 terabyte HDD for storage. No issues at all…super fast and reliable. There are great FOSS apps on F-Droid covering just about anything you’d need…the official app, cookbook, bookmarks, notes, news, etc. If you’re using an HDD instead of an SSD, just make sure you have a dedicated power supply for the HDD.

Just an FYI that you can definitely download shows/movies to any device via Jellyfin - just did so on my tablet yesterday…jump ship!!