There are simply people who are lucky enough to win bigtime. I think this is the reason why there are gamblers who are really into gambling. They are aware of people who actually won and became rich in gambling which may gave them the idea to do so, making other gamblers to rely that much in their fortune in gambling, which would boost their life situation. But that should not be the mentality of a gambler because it would more likely yield to gambling addiction and frustration, in my opinion.
They are blinded by the amount of jackpot they can possibly win in gambling and the idea that some people actually win big amount of money. Though you can certainly win in gambling, not everyone has that kind of luck and can experience such things.
These people on the list probably are the luckiest people. Winning such a huge amount of prize is a once in a lifetime experience that can change our whole life. We can also win (maybe not as huge as their winnings), but in order for us to appreciate it, we need to be contented with what we have won. Others can't realize that because they often use the money they have won to gamble again and ends up losing everything.
All of these wins seems to be in traditional online gambling sites that don't accept bitcoin or cryptocurrency. All of these are for Mega Jackpot or some similar scheme which are a rare winning on casinos. The ones that really won that are really lucky. But there are many instances of such jackpot being manipulated as these are not generally provably fair.