This isn’t entirely true. A stylus is easy to understand, as is paper. Buildings of stone are relatively easy to grasp as well. Being a polymath was once doable. Today to truly master anything requires a lifetime of dedication.

http://johnsalvatier.org/blog/2017/reality-has-a-surprising-...

But did the writer understand how the language got created and how the words shape her thoughts?

Do you know what went into Roman Concrete?

Do you know how to make paper? Can you? Is it any good? Do you really understand it then?

Plenty of people master more than one domain. It's actually easier when the knowledge is more accessibly distributed in more generalised form, so you don't have to find out how to build stone vaults that don't collapse by trial and error

Ancient civilizations were full of laws people didn't control and property they didn't own, enforced by weapons they had no idea how to make imported from regions they knew nothing of and would have no opportunity to ever visit. And you didn't really understand the priest's explanation for why the gods had determined your infant sons deserved to die any better than the average person nowadays understands the antibiotics that could have enabled them not to die...