Leave old movies seeding?

I love movies, and at times the websites I use to watch media do not have the movies I want, so then I resort to looking for torrents, which most of the time ends up in finding a torrent that's either stalled or has one singular seed. I downloaded a movie from 2003 (The Dreamers) last week, the torrent was created 4 whole years ago, and it took me around two hours to download it. I was thinking to myself, what if there are people who find themselves in the same situation, so I just left it seeding after being downloaded, if it weren't for these old torrents, I feel like a very big piece of media would be lost or forgotten.