The same reason libraries deaccession books even when they have spare shelf space, and, unless you are a hoarder, you get rid of/donate/sell unused items from y

The same reason libraries deaccession books even when they have spare shelf space, and, unless you are a hoarder, you get rid of/donate/sell unused items from your dwelling. Sifting through hoarded garbage has a huge cost - your time. You should not have to waste time even bothering to skip through garbage articles in an encyclopedia. Wikipedia editors should not have to waste their time reviewing updates to garbage articles, making sure the articles are categorized properly, etc.