Every casinos has it own requirements and many gamblers do not know this or maybe pay less attention to this aspect, some of this requirements were clearly stated in their TOS, nothing can change it because they put them there on purpose, gamblers always made a complain rue to their non compliance to these regulations and terms, ones you discover you can't cope anymore using a casino, you're free to go and try out others.
What is certain is that gamblers are too lazy to read the TOS in the casino. Hence, they forget what is allowed and what is not allowed so that when they accidentally make a mistake, they think it is permitted by the casino when the mistake is written on it. The casino. Casinos can change the rules easily but must let the users know so they won't be disappointed. And regarding the betting requirements before withdrawing the money, it already exists in the casino, especially if a gambler manages to win an event or promotion.