Physical deterioration results from:

Obsolescence refers to a state where an object or product becomes outdated or no longer useful, often due to advances in technology or changes in consumer preferences. While it can lead to the discontinuation of use, it does not directly cause physical deterioration of the object itself, which is primarily the result of physical wear.

Reversion generally refers to the return of an object or system to a previous state, often implying restoration or conservation rather than deterioration. This term does not relate to the decline in physical condition; instead, it suggests an improvement or maintenance of the object's state.

Accretion involves the gradual accumulation of material or mass, which can lead to changes in an object's properties but does not contribute to physical deterioration. Instead, it can sometimes enhance or alter the object's functionality or aesthetics, rather than degrade it.