This is the "too big to fail" that the GP described. Do you really want a world where a company can evade the law just by getting enough people to depend on it? An important idea of rule of law is that it applies equally to everyone, no matter how important they are. Once you make exceptions for powerful people or powerful companies, it can become corrupt and abused. No small local messaging app will have this protection that people demand should be given to Whatsapp. Why should the dominant player in a market be exempt from complying with laws that their competitors must follow?