Seriously, just looking at the examples of "stagnated and failing economies" like Japan should be a give away that this measure is total BS.
In Germany a life saving brain surgery creates 5K USD of economic activity and the same surgery creates 500K USD of economic activity in the USA.
True story, a YouTuber I'm following recently had her mother operated in Germany and then again in the USA and she made a video about the experience and the numbers:
https://www.youtube.com/watch?v=G-p1nP6hH6U
This obsession with GDP isn't healthy, among other obsessions like the "Number of gigantic companies" which is supposed to show that you are falling back in technology if you don't have extremely large companies by market capitalization metric.
It worries me because it's BS and BS can last just till a point. What happens if at one point in the future people start demanding benefiting from all that riches and success? I'm worried because I don't believe in(goodness of?) revolutions and the situation makes me anxious that the west with the US in particular is headed to some kind of revolution. They had one with the last election I guess but the revolutionaries appear to be pushing for the extreme version of the same thing which eventually might collapse with another revolution with the opposite thing like what UK ended up getting as a Labour landslide after Libertarian landslide.