Let me try: once you've reached a certain level of development, your priorities change. You don't care anymore about making more money than everyone else, you care about living a life you enjoy, even if that means you're no longer number 1 on something.

Other countries that are still on the first phase and do prioritize beating everyone else, to the detriment of their health and personal life, will start overtaking you... with time, they too will start giving some importance to a healthy life and will start falling behind (China may already have reached that point, as we now see some other Asian countries taking some pieces of the cake - helped no doubt by the West's antagony to China and its authoritarian government)... and so the cycle continues...

The countries that reach the top level in qualify of life, like USA, Australia and most of Europe, tend to still stay quite wealthy, it seems... as they still have a highly educated population capable of creating value for the country and their fellow citizens... so this story seems to be going well so far.

The lack of any major threat since 1991 has allowed them the political luxury of being able to make policy decisions based on ideology rather than objective reality. The Russian invasion of Ukraine and resulting energy crisis has demonstrated the failure of that approach so now they have to pivot. Expect a new wave of innovation led by the energy and defense sectors.