Some people I know who run money for a living think cryptos are simply a ponzi scheme. That was my initial reaction, but upon further review, I've changed my mind. I think their price movements are correlated to the fiat currencies of the people living in the countries where inflation is the worst. As an example, suppose you're living in a place where your local currency depreciates in value by half, relative to more stable currencies, in a few weeks’ time. From your perspective, an investment in say Bitcoin, before that decline in value happens, would be worth twice as much of your local currency, after the decline takes place. People in your country, with the ability to do so, would be getting out of the local fiat currency and driving up the price of Bitcoin. To you it wouldn't matter how Bitcoin's price behaved, relative to other fiat currencies. You just want out of paper that is becoming worthless. Meanwhile, people in countries with little or no price inflation would enjoy the benefit of rapidly rising Bitcoin prices relative to the values of their currencies.
This is an extreme example but in 1914, at the start of World War One, the dollar was worth 4.20 Marks. By November 1923 the dollar was reported to be worth 4.2 trillion marks. What if you had been able to convert your Marks to Bitcoin along the way? The price of Bitcoin literally would have "gone to the moon". Now suppose you had been sitting in the U.S. and also bought Bitcoin in 1914? You could have gone along for the ride and seen your Bitcoin go to the moon. Relative to your dollars in 1923, your Bitcoin would have appeared to be the best investment in history.
So my conclusion with crypto currencies is that they are not just a good store of value for people concerned about their country's local fiat currency, but they are a significant investment opportunity for people who live in countries where fiat currencies are more stable. Now, I understand there are thousands of voices berating all fiat currencies and many are predicting imminent disaster for the dollar. If those voices are right in the near term, the major cryptos like Bitcoin, protect you from inflation. If they are wrong or premature in their timing, cryptos could be the investment of a lifetime.
Please know this is simply my newly formed personal opinion. It is not intended to be investment advice.