Some blacklisted operators are known for paying extremely slowly, to the point where players are waiting months for any withdrawals they make. These delays can be frustrating, and it’s probably true that many sites could be a bit faster – but that’s not what we’re talking about here.
Furthermore, the sites have good reason to ensure that all of their rules were followed and that the player’s identity can be confirmed before money is released. Sure, some are faster than others, but there is processing time on both their side and the financial institutions they work with. Even at legitimate online casinos, withdrawals aren’t instantaneous.