A very interesting topic indeed.
The way I see it, something has got to replace this unsustainable debt-based fiat money system, and I believe Satoshi came along at precisely the right moment to introduce the first building block to our new financial base.
Do we really stop when our portfolios reach 1 million, 5 million, or 10 million? Or does fiat continue falling indefinitely relative to cryptocurrencies, and eventually the dollar value becomes completely irrelevant and we price goods and services in something entirely different.
Of course, our economies and society will need a complete restructure in order to run on cryptocurrencies (preferably the decentralized variety), but we have seen prior paradigm shifts in human system with the agricultural and industrial revolution.
One thing is for certain though. HODLing through the insane volatility, while constantly being willing to diversify into new assets as this technology evolves is a must for long-term success.