After registering in a casino, the casino gives new members some amount of money as a welcome bonus and with that money the new gambler can start gambling. This is a great strategy of a casino company, when a gambler creates an account for gambling, he may not be very confident in depositing money at first, so at first he does not hesitate to gamble with the money he gets as a bonus because he knows that this money has been given to him for free, so if he loses money by gambling with this money, he will still not get anything. In this way, when that new gambler starts gambling, later he sees that he wants to gamble more but he does not have enough money, then he deposits his own money and starts gambling with that money and this is the main purpose of the casino company to give gamblers a welcome bonus.
I can understand the logic of such a choice for a player who is registering at their first casino. In that case, yes, they might feel unsure, they need to try out how it all works, and it’s better to do that with a bonus balance rather than with real money. But if a player is already registering at their 10th casino, it’s unlikely that anything will be fundamentally new for them. And the bonus won’t help them get acquainted with the specifics of that particular casino, since completely different rules apply to bonuses than to real deposits. Therefore, the conclusions drawn from bonus play will not be relevant to further games with real money.