Such huge winnings with minimal investment in the casino are quite rare, so everyone knows about them, many bet small amounts in online casinos in the hope of getting a luck slot with a seven-digit figure or more, so I think these are unique examples of luck, but they are also motivating factors for many gamblers.
Since it is a big prize, every gambler shows interest in it and regularly bets small amounts there. Because they believe that if his destiny is able to give him that then he has nothing else to do. Many have such hopes. But the mentioned winners remain in the history. This is not always happen.