Simple proof for those two things at the same time. I have a friend, who is 1700 Elo. I am 1000 Elo. We played three games (unranked) together today, it wasn't like one of us was far better than the other, we were about equal. If two players of equal skill level can be 700 Elo from each other (Note: I have 80 ranked games and he 400, so it isn't like our Elo shouldn't be set already), then most importantly Elo ranking just doesn't work, and it also proves Elo Hell exists, as I would otherwise have carried myself out of 1000 Elo already.