Ability to write wasn’t the original literacy! It’s about reading. If you can’t read code or commentary about code how are you supposed to write good code or formulate new ideas about what good code should be and propagate those?
Then again, one could argue that the point of literacy is writing or creating in general. We transfer knowledge so that we can expand on it, not to merely consume it. You allure to it yourself in your concluding statement.
An old literature teacher tried to instill in us that we hadn't read until we had responded in writing.
What a stupid and flippant statement.
I wonder how much easier coding would be if we upgrade the user. There are of course combinations of many different upgrades to consider. It would also be interesting to discover a generic update is not worth it. I do suspect some occupations that currently lack them should not go without programming skills.