The difference is that with this kind of setup you have a somewhat similar experience to streaming services. You browse directly from the app and directly play the movie.
Torrent tip : if you make the download sequential you can start watching the movie using a player like VLC without it having to fully download. you start the download, wait a bit for it to load a few pourcentages and you can start watching while it’s still loading.
It depends on your internet speed, the file size and the movie length but if you’re internet is fast enough then no worries.