I think the issue that will always plague this is that firstly, when stuff is filtered through an app (ie not from the "source") there's a paranoia that something is being somehow missed.

Secondly, I like sifting through different sites (if they're built nicely), it adds variety - browsing is part of the experience of consuming content.

Also, there's an organisational overhead for setting up feeds. If you can just click on sites and explore, it's a different experience to adding feeds and refreshing. Consider it the comparison to doing your food shopping with a vague idea of what you want, and meticulously planning your groceries on-line and having it delivered. The latter is far more efficient, but the former is kinda fun in its own way and more entropic (which people enjoy in their lives).

I might be completely wrong, of course.