It absolutely is.
Doing it at all requires time & attentive focus, which is a finite resource for anybody mortal, and moreover a resource that's scarce and has to be spent in multiple places.
Doing it well requires significant investment in practice and training, often years of it, maybe even decades in order to develop certain levels of expressive fluency.
As with any issue of scarcity, economics comes in. If you want this activity supported, one good way of doing it is enabling the investment of time. Copyright does this by giving people an economic/legal claim on how copies of their work are distributed.
Paying for copies has the usual market merits -- the economic reward and signals of value are proportional to copies acquired. There are other ways of course, common ones brought up here are patronage and merchandising, but they lose the market merits, and both are basically another way of saying "nobody should have to pay for the value in your work directly," and merchandising is even worse in that it's basically saying "yeah, you'll just need another job to support yourself while you're doing this thing", which is time taken away from investment in the creative endeavor, so you'll get less of the actual endeavor.
Expression has no value in today's digital world.
Creation has value but using expression to exchange for that value is difficult, requiring limits on expression in order for the system to work.
The ownership, with heavy taxes on that ownership, pushes towards making sure people benefit from the land.
"goods are scarce because there are not enough resources to produce all the goods that people want to consume".(quoted at [1])
Physical books are intrinsically scarce because they require physical resources to make and distribute copies. Libraries are often limited by physical shelf space.
Ebooks are not intrinsically scarce because there are enough resources to enable anyone on the internet to download any one of millions of ebooks at close to zero marginal cost, with minimal physical space requirements per book. Archive.org and Z-Library are examples of this.
Consider also free goods:
"Examples of free goods are ideas and works that are reproducible at zero cost, or almost zero cost. For example, if someone invents a new device, many people could copy this invention, with no danger of this "resource" running out."[2]
It's pretty mysterious that you think you need to introduce this to the conversation at this point given how prominently scarcity dynamics figure into the comment you're replying to.
> Physical books are intrinsically scarce
Once their production was industrialized with printing press tech, copies of books weren't scarce, they were actually revolutionarily cheap.
The copyright bargain isn't borne out of ignorance of how changes in that direction affect the overall dynamic, it's borne out of deep understanding of what remains scarce and risky and difficult to compensate for when the marginal cost of producing copies drops drastically, and what kind of claims might help.
Authorship may be scarce - costly and resource intensive (LLMs notwithstanding) as you describe, while copying and distribution of intangible goods like ideas or digital media is essentially free and unlimited, as I suspect PP was trying to say.
As you correctly note, the constitutional copyright bargain permits a limited time monopoly in return for (hopefully) advancing "the progress of science and the useful arts."
"which people in particular are benefitting the most" seems to be the perennial question.
"Property is theft" is not a new idea, makes a lot of sense. Unless you have a lot of it, and then those [censored] can [censored] right off.