Bolide there is no question that at some point the item will need to be replaced usually at a greater cost sometime in the future. However many buy an asset (particularly a new investment property) now they have paid for that all upfront (albeit on a loan) but they shouldn't have any major expenses in terms of replacements for many years in which time they can use the benefit of depreciation to reduce their taxable income. Similarly you purchase a replacement item now sure it will cost you some money right now but you then get the use of the item and the depreciation benefits for many years to come before it has to be replaced again.
As with many tax benefits it is about when you can receive the benefit.
