We bought AppleTV last year because I wanted to be able to stream all our in-house movies to the downstairs TV for the kids. It’s all on an external drive connected to my little Mac Mini. It works great, and only $99. No way was I investing in a new gaming system for that. Have I joined the Borg? Yes, yes I have. LOL
You don’t need a game system for that. Could just use a chromecast, or firestick. Or heck since you’ve got the content on an external drive plug it straight into the TV. There’s a lot of ways to move content around your house these days.