Why aren't these used to steal cryptocurrencies? According to the article you can buy a similar exploit for just $1-2.5 million. Considering the amount of money

Why aren't these used to steal cryptocurrencies? According to the article you can buy a similar exploit for just $1-2.5 million. Considering the amount of money floating around that space, that it hasn't happened yet is surprising to me (or maybe I just don't pay attention to people who own crypto and are public about it, maybe they do get hit by zero-days all the time?).