The solution to these problems might be technically simple. Mostly because we're pretty simple in this regard; there are strong biological limits to the amount of information we can keep in memory. How we frame our experience of what we've seen before can be complex, but the way that it manifests in a system has to be simple or else we can't engage with it effectively and meaningfully.
So the key would seem to be breaking down the process of browsing to the elements being acted on and crucially maintaining those elements and actions, while at the same time adding possible actions. The concept of a "page," for example, is so fundamental to our understanding of the internet that it doesn't make sense to break it apart, for now at least. Nor does how we can interact with a page. So it's a matter of adding actions to existing elements. What else can I do to a page? Most broadly, how do we expand the space of potential actions?