$3B accounting error by The Pentagon
time.com
time.com
Hopefully this is the explanation.
For example, there's not a Dodge minivan vs Honda minivan depreciation difference, even though, if you've had both, you know one depreciates much faster than the other.
In the example below, it says 5 years for furniture. Is all furniture worthless after 5 years? Of course not. There's an entire industry of centuries old antiques.
"Depreciation is a non-cash business expense that is allocated and calculated over the period that an asset is useful to your business."
You ask How? More info here:
"Depreciation Concepts" - https://www.principlesofaccounting.com/chapter-10/depreciati...
example: https://www.myaccountingcourse.com/accounting-dictionary/ima...
source: https://www.myaccountingcourse.com/accounting-dictionary/dep...
There are depreciation schedules in taxation that let you offset your tax. To this effect, 100% depreciation would expense the item (and thus reduce the taxable income). Because the tax doesn't represent 100% of the value you paid for the item, it doesn't mean that the item no longer with value.
You don't want to sell working explosives (or, nukes) to random scrap yards but make sure they aren't working.
Cynically this "accounting error" is either an excuse to send more hardware to achive the same absolute $$ cost, or a method of communicating that the "cost" to the taxpayer was much (much much) lower than it really was.