Don't believe Buffett when he talks about crypto. He said the same things about derivatives while quietly being fairly active with derivatives.
I think the thing about crypto is to know what it can and cannot do for you. Bitcoin has exceptional value IF it becomes more adopted as a means for exchange. I give you 0.002 bitcoins, and you send me that pair of blue jeans in the mail. As that becomes more common, and easier to do, the demand for bitcoin will increase in kind, simply because it's effective. The demand for it will grow even more quickly if various governments continue to devalue their currencies by quantitative easing (i.e., printing money and the Fed putting a debt on the books). The value of bitcoin will theoretically be more stable (hard to imagine with its present volatility).
My buddy told me that Fidelity is going to put crypto on their platform, which, if I understood him correctly, would allow you to buy and sell various coins on their platform, in the same way you can buy and sell equities, mutual funds, ETFs, etc. I emailed my guy at Schwab to confirm, and ask him whether Schwab was planning to do the same thing.
If people like me having Schwab and/or Fidelity accounts, can easily buy/sell crypto and choose to hold as little as 1% of our assets in crypto as a hedge, the demand will grow substantially. As the rate of mining isn't growing substantially, supply/demand will cause the value of crypto to continue to grow.
For these reasons, I disagree with Buffett. Quite frankly, I think Buffett doesn't even believe what he says, but he's got a good thing going, and I see no reason to throw rocks at a genius. Besides, it was delicious watching him put Goldman Sachs over the barrel in 2007/2008 when he took 25% of the firm to provide them liquidity!!! Man, he raped those Wall Street arrogant a-holes!
My concern still remains. For the very reason why I think crypto will succeed above, the US gov't can't have it succeed. How will they sink it? I'm not sure. But beware a gov't hack telling you that government regulation is a good thing. Maybe in the short term, but eventually, the government has an exceptional ability to F things up. That is something that you can count on.