No doubt about the luck, no one will win such a big amount without luck regardless how much they have lost/spent before winning that huge amount.
Yes. You actually have a point there because such winning happens once in a many years, as there is a zero probability that a person's chance of winning is either determined by hong such individual has gambler or amount lost to Gambling. It's always as a result of luck, of which in most cases to individuals who least expected such huge amount of money