I do agree we we need to think at the individual level first. I means we have to think out of social/collective convention during this first step. Money is one of it. Desire is not. Let's start with desire, then figure out what we can do with money?
No, one needs money to prioritize one's desires relative to the availability of resources. Two persons might have the same order of preferences (A > B > C), but one person might rather have (A) alone, while the other prefers to have (B, C). By having an universal credits system, the two can bid on stuff and come out with a good compromise.
You'll notice that the crew quarters in the show are decorated in a minimalist style. The only objects people keep are the ones that are important to them. Tools, games, gifts can be conjured as needed and recycled when you're done with them.
Scarce resources do exist, however, especially on a starship: crew quarters are probably not all of the same size, for example. Some people might have to walk a little further to the turbolift (elevator). These sorts of resource allocation problems are likely solved by either a lottery method or based on need. For example, if the Captain gets bigger quarters, it's not because she's the captain, it's because she might need the space to host visiting delegates, etc.
Although I suppose there are still some material inequalities based on rank. For example, ensigns get a single rank pip, while a captain gets four.
When you think about it, there's a lot of stuff that'll still be scarce even when we have magic robots that can build everything instantly.
Many sought-after things are scarce. Starship commissions are scarce. They require hard work and are assigned based on merit. Not just anyone gets the opportunity to explore the edge of space; it takes dedication and sacrifice.
The show is certainly influence by the philosophy of Stoicism[0].
By the definition of economic scarcity it will be required to in order to merit the name. However, that illustrates that a post-scarcity society will never exist (or at least is vastly farther off than some people imagine), which is the more critical point.
If anything that anyone wants is limited such that enhancing one person's realized utility is a trade-off with someone else's realized utility, you don't have a post-scarcity situation.
Which is why post-scarcity isn't really something we are ever likely to need to worry about.
What we need to worry about is a scenario with scarcity where large masses of the public are (some in a static way, and some in a transitional way that, with optimal policy, could resolve given time), through arrangement of capital and the relative utility of automation vs. labor (including when it comes to producing additional automated production units) unable to contribute significantly to output, and thus have nothing to sell in the marketplace.
Additionally it would be 100% recyclable, with the idea that you would 'give back to the earth' when you were done with it (materialism would be a thing of the past).
Oh wait.
I'll never understand why people who promote this "magical robots solve everything" view ignore the simple examples that robots, no matter how sophisticated, cannot fix. For example, scarcity of prime real estate.
1. you have to build round existing structures
2. if the sea level rises, there is nothing you can do
3. small roads can't be widened to accommodate heavier traffic and so on.
In the future the concept of a fixed house would be bizarre, with everything being able to be made portable. It would be normal to have giant shifts in house placement and rewiring of pipes and electricity via AI bots, in order to accommodate change.
Why would the guy with the beautiful lake front property move his house? Why would he make his lot smaller to let other people live closer to him? What's his incentive?
Being able to easily move a house doesn't do anything to make lake front property less scarce.
If your answer is: "the government would force him", then that sounds more like a dystopia than a utopia.
People have been predicting this for some 200 years. It's older than flying cars.
Shared ownership allows you to drastically reduce the number of items that need to be produced. Look around you at the things in your house. How many of those things do you use on a regular basis, and how many things are under utilised for most of the time. Shared ownership means you get access to a much wider range of items whilst reducing the cost of ownership.