The difference is that you aren’t paying a monthly fee, have much greater selection, can download the file to play later (without the Netflix problem of content disappearing due to whatever contract terms are secretly in place), and using Movies Anywhere your purchases are synced to other stores. There’s still a lot of room for improvement there but it seems like you need to pick one model or another, not both.
This is not a very good fit for games, however: everyone sells and watches the same movie and almost nobody watches the same ones for anywhere near as long as gamers play them.
Yes, iTunes introduced buying films and TV in 2003 when the state of the art was an iPod. Very few people still do it and Apple is all in on streaming and has many affordances to seamlessly support first and third party streaming services through various APIs like supporting TV Anywhere globally, supporting third party apps in the Tv app, etc.