I'm active in the SSB community. These are just some anecdotes that might amuse you and maybe help you glimpse how I see the protocol and ecosystem.
I was on a transatlantic flight from Brazil to Paris. I had SSB on my computer and that gave me access to multiple years worth of messages by my friends and their friends. I spent time learning all sorts of cool stuff, and reading amazing convos. I could reply, like, interact with all of it, even without a network connection. Once I landed and my computer found a connection again, it gossiped all my changes.
The Internet was not working well at a conference. All the decentralization workshops and talks were suffering because of it. The local venue firewall was preventing them from reaching their DHTs and known services. We didn't noticed any of it as our machines were gossiping locally. Our workshop just moved on.
Wanted to onboard a friend on SSB. We were at a beach house without decent internet. I was using macOS, he was using Linux. Some other people were using SSB as storage for NPM and Git artefacts. I managed to get the source from a client from the SSB feed, copied over to him, and onboarded him by doing git clone, npm install, all from SSB.
A machine of mine had broken down — my fault really, I learned the hard way that renaming the single admin user on Windows is not an easy task — and I ended up having to reinstall everything. I reinstalled the SSB client, and copied over my keys. It restored all my data and feed by asking my friends for it.
> in practice centralization is usually fine
For many cases, yes. Centralization doesn't mean expensive or anti-privacy. I agree with you there. I don't think it is a binary situation. In many cases, centralization is the way to go.
I do enjoy decentralization though, especially when it doesn't rely on blockchains and cryptocurrency. I want my decentralization without financial incentives and cheap to compute.