First, the world has to answer the most basic question. Is crypto a currency (a middleman during a transaction) or a way to profit? If crypto is mostly about generating profits, then they are doing exactly what they should be doing: taxing profits. If crypto is a currency, then profits should be negligible and they are not doing enough.
A US penny is a form of currency. I can use it to buy items or services. I do not profit from holding the penny or profit from mining the penny or profit from holding a wallet of pennies. Does this describe crypto to you?
Maybe I'm misreading you, but people make money trading currencies every day in the FOREX markets, so I'm not sure what you mean. And even fiat currencies can be . . . well not exactly volatile - certainly not in the same way as cryptos. But you saw how the Ruble crashed and then kept digging. A lot of people betting on the ruble got their clocks cleaned.
OK, quick lesson in monetary theory.
The value of money is determined by supply and demand, just like everything else. Except that the price of money is the interest rate you have to pay to get some. More money with no change in demand means lower rates and vice versa.
Demand is determined mainly by the level of economic activity in the country(ies) that use the currency. But you also have to consider the level of international demand.
So for example, the dollar is considered the premier "reserve" currency. Other countries need to hold a certain amount of dollars if they want some level of liquidity in transacting business with US companies - as an example.
With fiat currencies, the amount in circulation can easily be modified by fed policy. So if the economy slows, the fed can release more liquidity and drive down interest rates to stimulate the lagging economy.
On the other side, if the economy is too hot - too much liquidity - the fed just sells assets and sucks that liquidity into the black hole they keep in the 10th sub basement of the NY Fed (that's a joke, I say, a joke son - nobody remembers Foghorn Leghorn. Shame. Such a classic).
Of course this pretty oversimplified but it gives the main broad parameters.
But notice what's happening in both cases. When we need money, we conjure it out of the ether. when it's being a pain in the ass, we send it to from whence it came. So in some sense, fiat currencies aren't "real" in the traditional sense of being backed by anything of value, like gold. It's demand that creates its value and that value can be easily manipulated.
But that's good. It's something that should have happened centuries ago. Monetary policy, in increasing or decreasing the money supply, can be used to stimulate a sluggish economy and turn down the heat for one that's pushing the economic envelope.
I hope that made some sense. Now let's look at cryptos.
The ones like BTC are primarily deflationary. What does that mean? There will always be a fixed number of BTC in existence - for all practical purposes. Of course I'm ignoring the ones yet to be mined but even those will eventually be tapped out.
So no matter how much or little demand there is for BTC, the float (available supply for trading) is basically fixed. That's part of why it's so volatile. Of course the main reason though is that its primary use is speculative. Remember the Dutch tulip bulb craze a few centuries ago? It's exactly like that.
So how does a crypto acquire value when it's actually just zero's and one's floating in the ether? Well, there has to be some "use case" that only BTC can satisfy. Very few cryptos have even a single realistic use case. In almost every case, their value is determined by speculators.