The building wears out, deteriorates, the tastes and needs of its users change. These are factors that lead to the demolition or reconstruction of a building according to the current fashion.
There are many examples of buildings being demolished for various reasons. One of the most outrageous was the demolition of a building designed by the famous architect Victor Horta.
The Maison du Peuple/Volkshuis (the headquarters for the Belgian Workers’ Party) was demolished in 1965, despite an international protest petition by more than 700 architects.
Facade of the Maison du Peuple, Brussels, Licence: CC0 1.0 Universal Public Domain Dedication, Source: https://commons.wikimedia.org/wiki/File:Maison_du_Peuple_of_the_P.O.B._
(Belgian_Workers_Party)_(destroyed,_Brussels),_exterior_2.jpg