Not everything is dual use. Some information technology grossly favors centralization or decentralization of power based on the type of information problem it solves.

Cryptocurrency is clearly a counterexample to your main point. The fact that some people use cryptocurrency tech to implement centrally managed private currencies is largely irrelevant. To the extent that cryptocurrencies are used to implement private currencies, it largely just hampers them technolgicially if it has any effect at all. These projects just like to use the term cryptocurrency to imply some level of legitimate decentralization or security that doesn't really exist.

It's like saying that because you can use a screwdriver as a weapon, it's inherently a destructive technology (or some mixture of destructive and constructive). On closer inspection it's clear that the screwdriver doesn't sit on the pareto front for weapons, but it does sit on the pareto front for manufacturing tools. So a screwdriver is clearly a technology whose existence favors construction over destruction. Similarly I would argue that technology like bittorrent or bitcoin favor decentralization over centralization.

As another example, surveilance technology favors centralization. None of what we are seeing now with flock would be possible without cheap mass produced digital cameras. The balance of technology favors cheap cameras (and counter-surveilance is often impossible or expensive) and it favors centralization because you need a lot of data to create inferences based on this spurrious data.

If we could have predicted these effects, perhaps we could have delayed the development of cheap cameras, but it just goes to show how complicated this game is. We could just as easily have said that more cameras would lead to unprecedented public transparency (e.g. bodycams on cops, dash cams). Unintended consequences.