I would say that wealth concentrating in a small number of hands is not a surprising outcome, nor is it a dynamic anyone with libertarian leanings can really be

I would say that wealth concentrating in a small number of hands is not a surprising outcome, nor is it a dynamic anyone with libertarian leanings can really be uncomfortable with. I'll admit I'm unpleasantly surprised by how quickly it happened. I would say that cryptocurrency has one advantage over traditional systems of money in that it governs with the consent of the governed - if the richest 4% of the cryptocurrency world become too aggressive and stifle innovation to protect their status, cryptocurrency's nature makes it very easy for the other 96% to take their ball and play elsewhere. There have been several 'hard fork' moments already (Bitcoin Cash, Ethereum Classic, etc) and what the majority of people went with was mostly determined by who inspired their confidence. I don't think Greenspan or Yellen could have gotten the majority of miners to switch to their system, that takes the confidence of the majority. So to answer your last question - I would expect the experiment to lead to a more brutal and cutthroat competition than we are used to, but I also expect the rules to be more fairly enforced, and the incentives of the rich and the rest to self-correct if they begin to diverge. I can't speak for other libertarians, but for me, finding that tradeoff worth it is what it means to be a libertarian. How clear-eyed I am about the costs I couldn't guess.