It's relative. I operationalize "why is X true?" as "update my worldmodel to the point that X is not surprising". The typical way to do that is to show a more g

It's relative. I operationalize "why is X true?" as "update my worldmodel to the point that X is not surprising". The typical way to do that is to show a more general rule that applies, and which implies X. But yes, you can keep asking the question about the more general rule. Why do things fall? -> A special case of the general law of gravitation. Why does reality adhere to the general law of gravitation? A implication of matter distorting the shape of spacetime. Why is reality such that matter distorts space-time?