"There's a set amount of wealth that can exist and the majority of it is already concentrated in the hands of a few. If adoption increases, the problem only gets worse." (reddit commenter on bitcoin)
Can someone refute this? If not, I don't want to get into BTC. I like the tech behind BTC transactions. But with 60% of BTC wealth held by maybe 1-5 million people, the above quote seems spot on, doesn't it? With 12 million coins already in wallets, there's less than 0.001 coins left for everyone else.
Preface: I'm likely not going to address your question directly, or adequately. Its a strange question, because you are fearing what already exists which is the concentration of wealth...Worse? The fact is the current landscape provides bankers and governments free reign to do whatever they want. As the tip of the iceberg, simply look at HSBC and their money laundering business. I don't believe wealth concentration can get much worse without enslaving the human race completely.
I agree with the other commenter; I also don't accept the question as it is presented but I'll still try to give you my thoughts on it. Specifically, I would like you to elaborate on the numbers you've provided and how you got them. I think you probably just copied them, which means you don't know if they are correct or not.
Also, what kind of adoption are you referring to? Adoption by investors? Adoption by consumers? They are two very different thing. Adoption by investors indicates a long term strategy. Adoption by consumers indicates functional utility that offers an advantage to competitive products or services.
Where the connection is made to BTC being concentrated in the hands of a few people is deontological not teleological. I agree with the assertion that increased adoption will result is greater distribution of BTC. This doesn't address distribution of wealth problems directly, but do provide a greater number of people with a functional transfer of wealth that is separated from the centralized power structures. This means thats you and I decide the value and cost of transferring that value, not the banks.
I believe the most important thing to acknowledge about bitcoin is that its decentralized and deflationary. Conceptually, this empowers the community and removes power centralized systems or groups hold over the community.
If A controls scarce resources, and if B values those resources then A has power over B. This leads to dependence and the ability to control in a way that uses B as a means to A's ends(profit). That is the situation with banks. They control the monetary system, and we all must use money to buy necessities such as food, warmth and shelter. So therefore, we willingly give power to the banks in exchange for the privilege of using their system to acquire those necessities. There's no law that says we must, but how many people do you know that sit at the farmers market on Saturdays to barter their goods or services for food? If alternatives are introduced (*ahem*, BTC) that remove dependence, then their power is diminished.
A major component of this power structure that banks and governments have created is controlling the flow of money. They decide how fast, or slow, and how expensive it is to transfer wealth. This allows them to very exactly dictate their profits, or the rate of concentrating wealth. If they cannot control the resource, their power is diminished.
BTC will not end the US dollar or fiat currencies. If they do die, it will because of market forces and/or legislation. At least if that happen, now there is a viable, proven, and secure alternative which can fill the vacuum that will be created because the function of transferring wealth must exist in some form. It seems like a natural progression of the human raced to move beyond a centrally controlled system (infancy) to a distributed, socially controlled and validated system of wealth distribution (adolescence). Maybe some day, the human race will achieve the next level of maturity. I don't know what that would look like...