Somebody has to do the hosting. Even if it s a federated platform, somebody has to care, federation just mixes up the content a bit. We should be demanding for public archives of people's information.
The problem is that aggregators dont make money from the hosting of the content but by indexing it/mixing it/recommending it. So they have no real incentive to store the content (but they do want the metadata). I think the solution is that we should all have publicly-provided storage space in the form of a free blog or email. Something very simple, could be just text/pics, that is at guaranteed not to be shutdown and is actually protected by free speech laws. Someone has to build the roads