I think you are missing the point here. It is not about if the technology exists or not. But when the community rely on it as the main way for following updates

I think you are missing the point here. It is not about if the technology exists or not. But when the community rely on it as the main way for following updates, it changes a lot of things. The quantity and quality of the articles. What does it feel to get a new update. I remember I was getting excited every time I get something new in Google Reader, Twitter doesn't feel like this at all.