Nostr is an inclusive communication commons

Let's not. Decentralization of power is not the same thing as accountability. They are alternatives that can achieve some of the same goals, but in significantly different ways.

My working definition is that a system is decentralized to the extent that a person cannot be banned from it.

I assure myself of a bed to sleep in in a decentralized way: there is a bed in my bedroom, in my house, which I lock with a key, so that nobody can sleep in my bed without my permission (or my wife's). Or I can go to a hotel, if I can find one that is willing to accommodate me, or to a friend's house. I am not accountable to anyone for my bed. If my bed has boxes of books on it and cannot be slept in, nobody will hold me to account. Not even my wife; she has her own bed. It is impossible to ban me from the Bed System, other than by arresting me; even if you took the bed out of my house, I could go over to my friend's house and sleep there, or I could get a new bed from a store, or from someone who's selling theirs.

This is somewhat inefficient. For example, tonight my wife is visiting her parents, so nobody will be using her bed. This kind of thing results in the community in aggregate needing more beds than people.

If I were staying in a homeless shelter, I would instead rely on accountability. If I arrived at the shelter and there was no bed available to me, I would complain to the staff. I would attempt to complain to the manager. I might at some point write a letter to their funding agencies. Depending on factors like my social status, I might or might not obtain some kind of alternative accommodation, and homeless shelters that systematically failed to provide accommodations to their clients might be shut down, or they might not.

If the homeless-shelter system in an area is completely centralized, accountability is all I'd have, and banning me from that system could be done at the stroke of a pen. But if there's some degree of decentralization, I might hoof it to another shelter, and perhaps find accommodation. Otherwise, I'm stuck either looking for a place to sleep on the sidewalk where nobody will steal my shoes, or maybe trying to find a bus ride long enough to permit me to nap in a seat for an hour or so, because I am significantly vulnerable to the centralized power of the homeless-shelter staff.

Despite its efficiency, this is considerably worse than my current actual situation, in which I really don't have to worry very much about having a bed to sleep in tonight, considerably lowering my stress level.

So accountability is very different in practice from decentralization of power. And that is why we prefer the Bed System, and most other necessities of daily life, to be decentralized.

In the case of Nostr, the idea is for relays to enjoy economies of scale without enjoying centralized power, in particular because they don't coordinate. There's always some tension there; if one neighborhood store stops carrying Sugar-Free Speed Energy Drink, you can go to another one, but there's no guarantee they carry it either. So the power enjoyed by the shopkeeper is definitely nonzero, even in ordinary commercial transactions (not to mention if they accuse you of shoplifting, which other shopkeepers might notice).

It's still much less power than that enjoyed by a big-box supermarket in a neighborhood with no neighborhood stores, and often economies of scale tend to drive neighborhood stores out of business when a big-box store moves in.

As an alternative to trying to decentralize your food retail system in neighborhood stores, you could try to centralize it and make it accountable, with a food co-op. If the co-op members don't like the food buying decisions of the staff, they can vote in a new board of directors that will fire the management, if necessary, in order to ensure better food buying decisions.

But this is very different from the decentralization of a diversity of neighborhood stores. Among other things, the food co-op can ban someone.

And even when it's not drugs, I sometimes use it to pay for things online because Visa randomly doesn't want me to use my Visa card for unknown reasons.