yet my point is that no casino offers 100 percent payout
Isn't it?
That there is no casino or gambling site that gives 100% payout is true because they are business institutional and one of the goals of making it is to get profit and profits are obtained from taking a certain percentage of each player's bet. But why can gamblers still lose all their balances because they can never know when to stop and be patient to start gambling again and greed is one of the reasons players end up with nothing.
Most gamblers go home with tears in their pockets. Only a handful of us go home happy because they won a large sum of money. So the house edge often wins. And sometimes there are even frauds that other gambling platforms do for players.
So sometimes, there are other gamblers who have already won a large amount but the other gambling platform makes a way or reason to not release the winnings of a player.