Accounting depreciation for assets is not directly related to resale value. Depreciation is intended to be an allocation of the purchase price across the whole

Accounting depreciation for assets is not directly related to resale value. Depreciation is intended to be an allocation of the purchase price across the whole expected usefulness term of that asset, it reflects the notion that in this year you "used up" some portion of an asset that will last for more years, so it makes sense to allocate just a part of the total cost to this year's cost of doing business. The intended purpose of that asset is to serve your business, not to resell it, so the fact that nobody would would buy that asset does not matter.