They should use the metric of purchasing power, not just an abstract "growth". If anything purchasing power seems to be dropping for a lot of people.
Why aren't we measuring how well the economy performs by measuring how healthy people are? Or levels of malnutrition? Or happiness? Or stress? Or education?
We should measure our economic progress by how well we're doing as people, not by how much extra shit rich people can buy.
It's interesting that economics doesn't usually factor in how much value is created by things that has a transactional value near zero, such as:
* a housewife maintaining a household,
* a person who quits work to care for a dependent family member, or
* open source software.