> I still don't see how the CPI is factoring this in, do you?

Because value = acceptable opportunity cost = foregone utility

And CPI measures (in closest approximation of any measure) changes in the prices of goods that provide direct rather than instrumental utility. Presuming monetary expansion affects prices but not, in first order effects, production possibilities and relative worth of non-money goods, a consumer price deflator is the most sensible kind of value deflator (one might still contest details of the construction of the CPI, of course.)