What is the benefit of written down method of depreciation and the straightline method of depreciation?

Presumption is in the early stage of asset purchased, it will work well.Its use value will come down as the day passes on.In written down value method of depreciation,more depreciation is allowed .In the latter stage, the depreciation will come down.

In straight line method of depreciation,the cost of the assets as deducted by the residual value of asset is divided equally over the life of the asset and charged to the respective P and L account.