I do not agree that forex could be any worse than crypto, after all they are both stuff that are very volatile, however the forex one is so dangerous and so slow to move that you have to use a high leverage in order to make any meaningful profit, take a look at dollar and euro parity, you will see that there is such a slow movement that you can't just buy euro as an American and hope to make a profit (or dollar for a European) straight up, you have to leverage it to high levels in order to profit from it and that means if you are wrong you are going to lose your money very quickly.

On contrary to that in crypto if you do invest into it directly and buy bitcoins and hold, you could double your money, even triple it. However if you were to leverage bitcoin that would have been same risk as well.