The aggregators are winning because they already do the algorithmic "comes to you" of content in their feeds.

That is, it's not like the web model of "surf anywhere you want" but rather "stay put and we'll bring stuff to you."

A few problems with this:

This centralizes a god-like power in the aggregator.

The emergent optimization function is engagement, not value.

It becomes an insatiable gravity well, sucking in absolutely everything around it.

The content isn't turing-complete.

That last one is key!

As Gordon Brander has put it, aggregators aren't open-ended.

This is not just a security model limitation.

It's also against the aggregator's interest.

Turing-completeness makes an open-ended system; one that can generate its own requisite variety.

If the ecosystem generates more requisite variety than the aggregator, the ecosystem escapes the aggregator.

An open-ended ecosystem would disrupt the aggregator.

It should be possible to make a system that:

Has the "experiences come to you"

Is turing complete

And isn't controlled by any one entity.