It's not quite precise to say that you're benefiting from depreciation. Depreciation is a real expense. It reflects a decrease in the market value of your asset. Expenses decrease income, which decreases tax, but paying less tax because you're making less money isn't a good thing.
Depreciation schedules are in some sense a legal fiction. For many classes of assets, there is an expense in holding these assets in that the value of the assets decrease. This decrease can be variable and difficult to calculate exactly. Because of this, many jurisdictions allow you to simply take a fixed schedule, regardless of whether that is the exact amount of depreciation. So if the amount that you're allowed to "pretend" the value of the asset decreased is significantly more than the amount that the value actually decreased, you will have less taxable income than otherwise. But all of this differential is eventually recaptured: depreciation reduces the cost basis of the asset, so if you ever realize a resale value that exceeds the "pretend" value, that is treated as a profit, and will be taxed. For instance, suppose you buy a car for $40k, you claim $30k in depreciation, and you sell it for $15k. Since there was supposedly only $10k of value left in the car, the other $5k is taxable income.
So being able to claim statutory depreciation rather than "real" depreciation is useful only to the extent that it differs from the "real" depreciation, and only to the extent that it is useful to shift your tax burden from this year to later years (which, since the income often comes in a lump sum, moving you into a higher tax bracket, may not, overall, be a benefit).
In addition, if we compare statutory depreciation to not buying the asset at all, the value is likely negative. If instead of buying that car, you had just set the money on fire, then (assuming you were able to justify this as a legitimate business expense), you would have been able to deduct all of the money immediately.
So to calculate the overall benefit, you'll have to somehow get the "real" depreciation (that is, some objective market value), evaluate how much value there is in time-shifting the tax burden, and also figure in the time-shifting effect of the initial purchase.
In short, this is a huge amount of effort and guesswork in pursuit of some mythical "true" value. Accounting isn't about some sort of perfect reflection of ontological reality. It's about methods of recording money flows, with reasonable approximation of reality being one goal, but standardization and understandibility being other important one. Creating ad hoc systems to chase after what you think "should" be included is fraught with problems. In addition, it means keeping two sets of books, one recording what your financial status is according to tax accounting rules, and one according to what you've decided your "true" status is.
Record the depreciation as an expense and move on with your life.