We can't really call the mentioned examples as biggest wins unless we know how much the players have lost before hitting it and how much they have spent on gambling from that money. But there is no doubt those are huge multipliers we don't see everyday.
The risk is the same (same odds for any other player). It's just those players got extremely lucky and hit the jackpot, which is something I envy them for.
From each bet amount in the list of the biggest wins above, it is not included in the list of big gamblers, but all wins are purely because of the factor of getting the jackpot, so everyone will be jealous to see it if I get 10% of the highest winnings already very happy, their lives are billionaires now for buy various goods and luxury homes.