Depreciation and Depletion are two entirely different concepts.
In depreciation, you can depreciate more than the total you paid (usually about 2x). The rationale is that your depreciation, over the depreciation period, would capture the value of your declining asset. Different classes of assets have different depreciation periods and schedules.
In depletion, you are doing a straight line deduction where the maximum deduction is equal to the total you paid. You see this concept applied mainly to things like oil wells and intellectual property (e.g., you buy the Beatles catalog for $1B and it will go into the public domain in 100 years, so you can deplete it on your tax return under a straight line deduction).
For open ended timeshares, you can't depreciate because you don't own enough of the timeshare to make you an equitable owner, and without an end date it is likewise ineligible for depletion.
But, I believe an argument can be made for
DVC's fixed end date making it eligible for depletion.
I'm not an accountant, and I urge you to engage one before filling out your tax return using my opinion.