In my case - of course it takes up space that would otherwise be free. I only get what I immediately use and I mostly don't need it anymore directly afterwards. If I'd only seed as long as I need the file I would never reach a ratio of 1, let alone 2. So yeah, a ratio of 2 leaves enough space for me to work with, while giving back double then what I took. I don't see the problem.

unless you were planning to delete the thing, which doesn't make much sense

Why not? You keep every film every episode every-thing you consume?