I was thinking about what economic system can work best in the future to maximize human flourishing.

For Western civilization, I would say the closest I have right now is something like Balaji Srinivasan Network State. A distributed decision making with a limited federal government responsible only for defence, federal law and federal law enforcement.
Which basically means an echo system of separate jurisdictions, each with its own education, healthcare social and tax policies. But allow free movement of people and capital between systems. Run different experiments in parallel.
i.e. some states can experiment with social democracy and high taxes. Some with free markets and low tax. Others can experiment with completely new systems.
People and capital will move from the less successful systems to the more successful ones.
How does that apply to Massasutests?
Allow than to implement wealth tax.
The alternative is a global totalitarian system where decisions and policies are made by a central authority. Similar to China or a more powerful UN.
Both distributed and centralized systems can work. I think a distributed system is more suitable for Western Civilization. And is also more resilient to collapse.