A good average is 4 hours per page, which is needed in phd / thesis writing. On the internet, sometime higher values are discussed. For example i've found many posting in which the total amount for a phd thesis was given with 3000 hours over 7 years. And the result was a 200 pages long phd-dissertation. According to a short calculation this is equal to 15 hours per page.
But how can we minimize the value? At first it is important to know, that in reality the effective productivity is in between these borders. That means, it is not less then 4 hours per page and not more then 15 hours per page. The main problem with thesis writing is, that the writing itself can only be done as a result of studying. That means the workflow consists of reading existing literature, thinking about, making experiments and writing down new information. Sure, it depends a bit on the needed quality and also the subject, but there are some activities which are equal in all domain. In the minimalistic form the workflow contains two parts:
1. reading existing literature
2. writing the own text
This is called minimalistic because all the other steps like proofreading, formatting, doing experiments and filtering out not wanted results are missing. It is not possible to shrink the workflow further. So I'm sceptical if it is possible to need less then the above mentioned 4 hours per page. The only exception is Artificial Intelligence, for example the IBM Watson software which is – in theory – able to generate short text. Such a textgenerator needs indeed less then a second for producing content, but in reality most papers are written by real humans.
The problem is, that even with modern technologies the productivity is not very high. And even experts in academic writing are not able to increase their productivity further. That means, even if somebody familiar with a subject and an expert for English language, he needs some time to write a text from scratch.
But in reality, the bottleneck isn't a real problem, because it is possible to increase the number of students. If one student can write in one week a 5 page long paper,then 10 students can write in one week 10x5 pages and so on. I'm pessimistic if it is possible to increase the subjective productivity of an author, but it is always possible to increase the group-productivity. The average author is able to type in an average quality paper. It is not a mark 1 but it describes a topic. If there is a need for more academic paper this can be fulfilled by more students who are writing such content. The interesting fact is, that the world has around 7 billion people which is in theory an unlimited reservoir of academic writers.
The funny thing with any electronic document is, that after it is created once, it can be copied many times. A pdf file doesn't loose his quality if it is downloaded 1 million times, it remains the same data. If the content is available at the internet, all the people can profit from it. That means, even if the generated content has a low quality, is about the wrong topic or was written in the wrong language it will always improve the Gutenberg-galaxis. It is not possible that somebody can weaken the overall accumulated knowledge by adding new information. The only possibility is to reduce the amount of information, but that is technically not possible.