This is true and is probably why IA doesn't re-encode them. However, if you just want your own personal copy to re-watch them I don't think this is really that

This is true and is probably why IA doesn't re-encode them. However, if you just want your own personal copy to re-watch them I don't think this is really that big of a problem. Ideally IA would keep the originals for archival purposes and make re-encoded versions available as well, but I expect they don't because they have limited resources.