The Gompertz function does not measure ageing.

The Gompertz transform of the distribution function for the age at death expresses mortality in a form R = R0e(alphat) where R0 is the mortality at time zero and alpha is the rate of increase of mortality, frequently taken as the rate of ageing. The slope of the line alpha is frequently used as a measure of the rate of ageing. It is argued that it is incorrect to use alpha in this way. To support this contention, a paradox is produced whereby selection for longevity increases alpha, which could lead to the absurd conclusion that selection for longevity increases the rate of ageing.