When you grant a monopoly over items that have zero marginal costs, you are creating massive dead-weight losses. The reason that we use artificial scarcity is because then we can use supply and demand on that, and use the funds to reward the creator.

There will always be new things to create. Some think that because IP is a monopoly, you should tax the monopoly. But that's going at it from the wrong direction. Creating new things produces a positive externality to others. You want to reward that. This is a scheme that might possibly do so.

I'm sorry, I don't understand how any of this responds to my questions. I didn't ask about monopolies, I didn't ask why artificial scarcity exists, I didn't ask about intellectual property.

You asked how to have an economy without scarcity. There will always be certain things, like natural resources, that are scarce. You can not make more land. Those things will always have scarcity.

There are other things that have zero marginal costs, and can indeed eliminate scarcity. But if you eliminate scarcity on those items, there becomes no incentive to create new things, as the natural price of anything with infinite supply is zero.

The creation of new digital items needs to be balanced with the very real scarcity of natural resources. The essence of your question is - how do we reward the creation of things if we can not restrict the use of it? And so we need to find a way to figure out the value of infinite supply items.