Plex also lets me easily share my movie rips with family members across the country.
I’ve tried Plex in the past and wasn’t a fan of the bloat and constant changes. I’ll stick with jellyfin since it’s free and doesn’t have the negative incentives associated with pursuing profit. I find that annoying when o just want a clean way to watch my library.
Not sure about AppleTV, but fyi note that there's currently 2 official apps: "Jellyfin" and "SwiftFin".
SwiftFin is better but very new and doesn't have all features yet, etc.
Even my most recent ex, who's nearing fifty and has never been especially at home with tech, found nothing objectionable about using it via the iOS native app - with the content of my library, yes, but that's no more fairly blamed on Jellyfin than it would be on Plex.