You raise some interesting and relevant points.

Re the centralized mining, I believe that Satoshi never intended mining to be as centralized as its become. In fact, he may have believed that it would be much less centralized. Nevertheless, it's most likely that the centralization was inevitable

As you pointed out, in certain ways, the crypto field is like the current economic system. But at least the crypto space does not have the rampant fraud, the centralized power, and the counterfeiting (aka QE, aka money printing) of the fiat money system.

As you stated, the big players in the crypto space cannot manipulate the crypto prices as the banksters do to their currencies.

Re volatility, we can be certain that all overvalued fiat currencies will soon prove to be very unstable and very volatile. And we can be certain that their volatility will occur in a very steep downwards trend.

So, I'll take the minimal volatility of cryptocurrencies over that of fiat currencies any day.