Obsolescence
Obsolescence is the state of being which occurs when an object, service, or practice is no longer wanted even though it may still be in good working order. Obsolescence frequently occurs because a replacement has become available that has, in sum, more advantages compared to the disadvantages incurred by maintaining or repairing the original. Obsolete refers to something that is already disused or discarded, or antiquated. Typically, obsolescence is preceded by a gradual decline in popularity.
Wikipedia
Obsoletion (noun)
Obsolescence.
Obsolescence (noun)
The state of being obsolete—no longer in use; gone into disuse; disused or neglected.
Obsolescence (noun)
The process of becoming obsolete, outmoded or out of date.
Wiktionary