I would push on how well GDP measures "economic might".

If I were to tell you a country over five years grew its GDP 5% in 1900, that would mean houses and roads and factories and mines and a whole range of things were built.

In 2020, 5% real GDP growth could be an increase in the value of various services. In fact, you might not need to change the physical world at all to achieve that growth.

Services are all basically a proxy for the physical world though. Other than things like art and media that people value for their own sake.