All this is part of the (somewhat complex but beautiful when it works) standards and services that people from the IndieWeb movement are shipping. You can see more info about it at:
Of course if you’re thinking in terms of “broadcast internet” with a Facebook at its center you may be correct
There is still a difference between cache and what's on hard disk.
The system works quite well, and I can read my RSS both via a client-side app (thunderbird in my case) and on the go via the webmail. I even made a small modification to rss2email to automatically "tag" the mails so I can use mail filters to automatically sorts the feeds into different folders.
I have a server that fetches the RSS content a few times a day, but I guess it could also work "locally", for example by doing it once each time I turn on my computer (if you are okay with "missing out" sometimes on very active feeds).
I decided to do the switch when I noted that the interfaces of my email client and of my RSS reader were basically indistinguishable.
EDIT: for the anecdote, this project was initially created by the very same Aaron Swartz that, among other things, contributed to the creation of the RSS format http://www.aaronsw.com/weblog/001148
A lot of email clients also have support inbuilt. (Thunderbird, Outlook, and others).
So basically WebSub but you don't need to run a WebSub server - you could just parse feeds using, for example, a procmail script. Email is already a well-supported protocol; WebSub is not.
In AP you don't need to follow anyone to have messages for you delivered directly to your inbox.
You have to check other servers if you're interested in messages to others but I guess there is no analog to that for email.
(My blog's currently down due to too much unrelated tinkering).
Oh good, I'm not the only one with a broken blog:) I discovered recently that while my blog is up, I didn't have source files that would generate the site as it exists on the server. Nice to know other people have similar things going on:)
ActivityPub is still experimental, and you may not even need it.
My blog's content is natively shown inline with other content on Pleroma. To a Pleroma user, it and responses seem like all other native posts and interactions. They can click its ID to go through to my original blog. There, everyone sees my blog and its style, as well as the same responses as native comments. Back on Pleroma, those users can boost it and share it with others (their followers). Virality achieved. No further engineering needed from me to enable that.
That's federated social networking. Imagine writing a YouTube comment from Twitter's interface and your Twitter account. In this case, my blog's content -- not just links -- natively pops up in followers' feeds when I publish something. And since ActivityPub is built on and compatible with RDF, this could be extended to all sorts of domains and interactions.
I am probably underestimating the complexity of the problem, but I have a feeling that this is a "I hacked this together in an hour and it works a lot better than expected" type of problem.
Because XMPP Pubsub is basically a container for anything an https://xmpp.org/extensions/xep-0277.html already fully standardize the presence of Atom 1.0 in XMPP it's super easy to publish standard RSS/Atom feeds to XMPP and enjoy fully real-time, decentralized news system.
There is no need to "fake" an ActivityPub account or edit your articles content, the feeds (called Communities) can be managed with roles, subscriptions and many other features and the articles are basically standard Atom elements (like you can find on your average HTTP Atom feed, the container changes, the content stays the same).
All those things are already standardized for years (Pubsub is there since 2002, Microblog since 2008) and implemented in the main XMPP servers.
If you want to check things client side, I'm working on Movim that implements all those things already https://movim.eu/.
Here is the XKCD feed on XMPP Pubsub https://nl.movim.eu/?node/comics.movim.eu/XKCD and our Movim Blog https://nl.movim.eu/?node/pubsub.movim.eu/Movim (notice the likes, the comments, the edited content, the rich content)…
What's the reason for using non-standard ports?
Unfortunately we cannot change the existing URLs that were spread across the whole network so we're keeping an exception for the existing ones.
But the new files are now uploaded on this kind of urls https://upload.movim.eu/files/9d94237298995552fa13436420195f...