If suffering is illusory, why can't an enlightened master change the illusion and liberate everyone?
Good question. Yes, suffering is illusory and Samsara is an illusion also. Those are illusions created by the mind. But these are created by your mind, they are yours, personal illusions. And everyone has slightly different ones. Some aspects of them are universal, as we all share the same culture and Samsara is basically creation of society, but it’s also very deeply personal.
So, everyone lives in a personal world of their own making, created unconsciously. Making it all conscious is basically what enlightenment is, and it’s not pleasant, but that’s the path to liberation.
No enlightened master can help you do that directly, liberate you or remove all your pain and suffering. Only you can. They can only help you with advice and guidance.