I’m given to understand that some technophilic strains of the left believe that Bitcoin is a liberatory technology, because it frees currency from the control of state and corporate interests. However, the price of this liberation, as far as I understand, is that effectively no one controls Bitcoin as a currency. Now that the algorithm has been set running, the supply of Bitcoin will expand based solely on user interest, until it ultimately hits an arbitrary limit. This means that as a currency, it will be subject to massive and permanent deflation once it reaches the limit, and in the meantime there is no way for anyone to manage the supply of Bitcoin or its value relative to other currencies. And of course, people are expending a huge amount of electricity “mining” Bitcoin.
In my opinion, fiat currency is far preferable. Yes, it is currently a tool of the big banks — but it’s also the most powerful and elegant tool of economic management ever devised. Even if one doesn’t go as far as Modern Monetary Theory‘s claims about its potential as a liberatory technology, in the postwar era fiat currency was in fact used in a broadly pro-worker way in Western countries. It’s being used to neoliberal ends now, but so is everything else.
And so, though I understand the distrust of actual-existing monetary authorities, I don’t think that humanity needs yet another way to surrender our collective decision-making responsibility to an impersonal economic mechanism. Working toward a People’s Central Bank — or, failing that, pushing for reform of existing central banking systems — is a much more promising venue than Bitcoin advocacy.
An und für sich 
bitcoin was modeled after gold; hence it has to be “mined” through incredibly energy-intensive computational processes. It’s explicit nostalgia for the gold standard by anti-inflationary (rich) types, that was latched onto by other rich types as a potential mechanism for even more rapid rapid-transaction financial trading. The whole thing is unveiled technocratic class warfare.
That being said, possible left bitcoin-equivalents have been developed to use electronic platforms basically to organize non-capitalist economic networks (like this one? https://www.community-exchange.org/ ) I don’t really have a settled opinion on these, but it seems more on the utopian-separatist than the political-antagonistic side of things, so agree that organizing for fiat currency becoming the financial mechanism for a better class position again is prolly the way to go.