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.
That is the attractiveness of those games, while in a game like blackjack the house edge is small and your profits are also small, there are other games in which the chances of winning are very low but in the case you win your life could change its course due to that single win, so each game has its own characteristics and they appeal to different kind of gamblers, with that being said people still need to be very careful and only gamble for fun even if deep down we wish to win.