If they couldn't manage it properly or doesn't know what they are doing then the outcome is almost certain that they would only lose in this field.
Investment and trading couldn't make you rich in just a short spam of time it takes time to learn and surely it would take some time and experience to earn from it.
People who think that way about cryptocurrencies and the investments made in this industry are the ones who are misguided and have a misconception about the whole market. They see news and stuff about how some people have managed to become millionaires after making small investments in cryptocurrencies, but they don't have any idea about how that happens, it is stories of some of the meme coins that have managed to provide great profit to their initial investors which then becomes a motivation for a lot of people to become cryptocurrency investors.
Someone who learns a little bit about the industry will come to know that trading is not a get-rich-quick scheme and it is just that some people get lucky and manage to earn significant returns in a short period while others have to work hard to earn money in this industry.