Netflix, you indeed lose your time but you don't have that feeling that everyone else is having a wonderful time while you are losing yours on the couch. Netflix (as TV) provides some healthy entertainment.
Facebook on the other hand provides entertainment by broadcasting how perfect other people's life are. And this is exactly what pushes people to depression and suicide. Ask people you know and most of them will admit that after their daily visit on Facebook they feel a bit burned-out. This effect is also magnified because you now always keep in mind that you should post a "perfect picture" on Instagram to please your followers.