There is only high "depreciation" in the beginning in cases where buyers overpaid. MSRP is not a real value, it's an inflated number created to facilitate lending too much to underqualified borrowers.
If you compare the real market prices from new to each year older 1-5 the picture is more realistic.
The delta between selling price and buying price is also a consideration. New or used, the dealer will purchase at wholesale and sell at retail. Pay that gap once in ten years and amortize it it's not a big deal. Do a trade in every year on used units and it'll eat your lunch.