What do you mean there can be no profit in such spiral?
I think purpose of BTC is not to replace FIAT money but to be a safe, decentralized, private form of asset.
Most people are doing fine with money system we have now. But imagine some people who doesn't have access to bank. They completely depend on their government. Their savings from whole life can become worthless in matter of days. And they can't do nothing about it... until Bitcoin. But for now FIAT money is still indispensable. So cryptocurrenies are just another form of asset.
What do you mean by connection? Cryptos are not backed up by anything physical only by their security. HAHA taxing in favor of people... Cryptos are first form of money which is not controlled by anyone. Only by math. I don't even know how would this make it more decentralized???
We are still in early stages of blockchains, so there is a lot of room for improvements. And of course price wildly fluctuate if the market is still so small.
''An economic bubble or asset bubble (sometimes also referred to as a speculative bubble, a market bubble, a price bubble, a financial bubble, a speculative mania, or a balloon) is trade in an asset at a price or price range that strongly exceeds the asset's intrinsic value.'' source:
https://en.wikipedia.org/wiki/Economic_bubbleSo yes we are gambling with bubbles, crypto currencies will be overvalued due to ''stupid'' money (people which are investing when they see big increase of price in news, but of course that is the WORST time to buy). But in the end they will still be worth a lot.