There are a number of web servers that host content (either for free or for money) [called relays].
Clients download recent posts
Identity is based on public key, allowing users more control and the ability to easily change relays.
So is RSS + pubkey based identity the right way to think about this?
Initially restrained from posting it, since it's possibly rather grumpy, and the authors seem to have fun with the protocol, but here it is.
The protocol doesnt want users to run their own servers, but there also aren't really any incentives to run relays, so what happens when it gets big enough that running a relay is expensive or non-trivial? I feel like it would just fall back to users running their own servers like in mastadon.
Relays have to figure out how not to get smashed with too much data. I predict they will require an account/login at some point. But you can post to multiple relays and drop relays that don't serve you well at any time.