From a physical perspective, information is a representation of some kind of state or pattern in a physical system. According to the laws of thermodynamics, information cannot be destroyed or deleted, only transformed or transferred from one form to another. This is because information is a form of energy, and according to the first law of thermodynamics, energy can neither be created nor destroyed, only converted from one form to another. Therefore, any information that is deleted or erased must go somewhere else, either in the form of heat, light, or some other kind of energy. Furthermore, the second law of thermodynamics states that the overall entropy or disorder of a closed system tends to increase over time. This means that any attempt to delete or erase information will inevitably lead to an increase in entropy, as the system becomes more disordered and chaotic. In summary, physical laws dictate that information cannot be completely erased or deleted, as it can only be transformed or transferred to another form of energy.

That's an incorrect explanation. Kind5/deletion and physically erasing information are different. Both kind5 and kind1 are event types that enter the nostr system. Kind1 is a declaration of the userdata's right to exist in the nostr universe, while kind5 is a waiver of the userdata's right to exist in the nostr universe. Although kind5 is opposite to kind1, it does not mean that it will increase the entropy of the nostr system. For example, it can delete spam or tell the relay that a certain note is no longer needed, allowing the relay to prioritize deletion when storage is critical. These actions are obviously helping to reduce the entropy of the nostr system.