Isaac Arthur has done some wonderful videos on the future, and several that stand out to me detail a post scarcity civilization. As an author, this was a valuable resource.
When I created the world of my novels, I wanted there to be different pockets where some were post scarcity, and others were still driven by profit. I created a human civilization at the cusp, where one segment, those on Luna, have gotten there. Full post scarcity. While others, those in the Corporate Federation, still value profit above all else. The unfolding story will begin the final transition from one to the other, but it's a painful process. People tend to get in the way of change.
The method I came up with for luna was the idea that every child is born with one share in the Lunar Sustainability Cooperative. And when a loonie dies, that share goes back into the pot. While they are alive, the system credits them their share of the profit, and deducts their costs. In this world, everyone is technically a billionaire, and never needs to consider what something costs. Within reason, anyway. Anyone can live a decent life, be well fed, and do any creative activity they choose to do, including not being creative at all. The laws of the world are automated, and simple to understand. Hurting other people accidentally comes with stiff penalties. Doing it intentionally can get you thrown out the airlock without a vacc suit. Overall, people find creative outlets that they like and share when they feel like sharing.
All of the infrastructure, all the mining and maintenance tasks are either automated, or done by volunteers. Farms are run by a mix of automation and people with a desire to grow things. Restaurants are staffed and operated by people who want to do the work. All of the economics are hidden, behind the scenes.
The only lunar government I present is the Assembly, which is usually called once a century for a checkup on how the system is running, and then upon the occasion of an emergency, such as when there is a problem the automated systems cannot cope with.
And yes, my first book, Final Assembly, has one of those latter situations. That's been sent off and I am working on more stories in this universe.
I am assuming that other groups of people get together, from time to time, to make adjustments concerning their communities. It should also be assumed that these folks get the approval of their peers along the way. Lunar society is a group effort.