Benefit of scaling survey design weights

Question

In the european social survey the design weights are scaled to the sample size (see quote and source):

As with the design weights also the post-stratification weights are scaled to the sample size, i.e. the initial weights provided by the post-stratification procedure are divided by their arithmetic mean. (page 4 of pdf , see link below)

Source: https://www.europeansocialsurvey.org/docs/methodology/ESS_post_stratification_weights_documentation.pdf

I dont really see the benefit of scaling the weights compared to keeping them as is, if they are unscaled after post-stratification. What is the benefit of this procedure?