Money management has always been a problem, with people failing. As Helena Yu said, it doesn't just happen in the crypto world; it happens in almost every industry. People then try to impress the world with luxurious lifestyles that cost them almost everything, living the rest of their lives in regret.
I have listened to a financial advisor and there was a statement that he made that made me think twice and even till today I am still ruminating the statement. He said that it is more difficult to keep money but easier to make money. He went further to say that if you check many people around you they have handled thousands and millions at a particular time in their life but then they were unable to keep this money till another time of their life that they are unable to see such amount of money again. At a point I had to agree with the advisor. Money is hard to make but harder to sustain but in all it is very easy to spend.
I have heard of a lot of smart people who lack financial knowledge but remain successful because they are wise in other aspects. For instance, I have heard of individuals who made a huge profit from Bitcoin, and because they couldn't handle it, they just employed people to teach them or help them invest, and these experts helped them maintain this wealth, so they didn't fall back to square one. The fact is, even if one is not money-wise, they should be wise in other aspects.
I am not comfortable believing this story of yours you told. If someone had invested in Bitcoin and made huge amount of money he should be considered financially literate and not to meet any other person to teach him another type of investment in order not to return to poverty. I put it to you that anyone who is able to invest in Bitcoin and have good returns has already known the methods of investment and does not actually need to employ any other person to teach him where again to invest.