I disagree. A decentralised system like Bitcoin is similar to a democracy in that users can signal support for any changes that they want.
Well, the basic tenet of decentralized systems is that in principle, the entities never collude with majority. For instance, if a majority of users support the change to reverse part of the block chain, on the proposition of a single entity (every proposition has always to come from a single entity), then we can say that this majority "applied a 51% attack" on the system.
Now, I perfectly well agree that this is a possible dynamics of the system, but I would think that from the moment that a majority colludes over ANYTHING else but "sticking to the rules", it is centralized in a way. To me, decentralization means "no collusion of any significance between entities".
That said, you are right that one could have a more sophisticated system, in which the basic rule set allows one to propose new rules (as "modules of code"), to be sent by just anybody, and "voted" over by those that make the consensus (say, miners if PoW, or whatever system), automatically. As such, there is no "leadership by devs". There can be an automatic code activation mechanism if X% of the last consensus decisions were positive towards this module, in the same way as the 95% rule in bitcoin for soft forks.
But if such system isn't in place, then the only way to be able to modify anything, is by obtaining a collusion of a majority, which is the same thing as a 51% attack, defining the end of decentralization, in my eyes.
You could look at it like proportional representation except each "party" is a mining pool, and the mining pool have a naturally created threshold for being relevant which is a high enough percentage of the hashrate for people to mine there.
Yes, but democracy is centralized, and "obtaining majority by coalition" is exactly what "majority collusion and cartel formation" is about, and which decentralization was supposed to avoid.
Even in most major PR-based democracies, the country ends up being a collection of just a few different parties with different proposals, often claiming to have the same goals while having different ways to get there. Eventually either a majority Parliament is formed in these democracies, or there are problems which eventually have to result in a coalition (a compromise or a chain split in Bitcoin's case).
I agree with you that most initially decentralized systems have "economies of scale" in them that lead to centralization, and cartel formation. Party formation is such a form of centralization of initially decentralized democracy, where each representative was supposed to NOT TO COLLUDE with others in a significant way, but ends up doing so, because it is the way to win elections: to form cartels that have economies of scale in winning votes.
Bitcoin is very comparable to these democracies and can therefore change while still, in theory, being decentralised.
Well, in my book, that's a centralized system, because there is collusion between entities. Decentralized means, no significant collusion between entities. Because *if* you think that democratic systems are decentralized, then you should also conclude that all their decisions are decentralized decisions, and that, for instance, the financial system is sound too, which makes crypto ridiculous: after all, a decentralized, democratic system decided upon how payment should ideally happen. So why start another system ?