>If you view a change in currency as fundamentally pretty useless, then yes, giving massive amounts of financial control of resources and labour(which is what money represents) to people with BTC hoarded does indeed take away from others.
People are voluntarily paying them for their coins because they, for whatever reason, value them. You can say that's silly but it's not like you are being forced to buy bitcoins or anything.
>And if BTC were to become (for instance) a primary currency for a country, and that country were to experience economic growth, then deflation must necessarily continue.
Isn't the same true for any other finite resource? Everything will deflate/increase in value relative to rest of the economy.