A dollar today is worth more than a dollar next year, even with zero inflation
Money available now can be invested, lent, or put to work earning more money, so a guaranteed payment today is worth more than the same payment delayed — independent of any price rises. This 'time value of money' is why loans charge interest, why lottery winners are offered less for taking a lump sum, and why every serious business valuation discounts future cash flows back to what they're worth right now.