I actually am. I'm well aware how long writing a book takes, how writing is rewriting, how editing is rewriting again, how copy-editing is rewriting again again
I have actually written a full book (well, a novella), talked to agents... and in the end failed to place the book at a publisher. Which, yes, means I was not successful while this manga was. I admit that. But it also gave me some insights
I also have aquaintances who were successful where I was not, whose process I got to see
I do have some idea, yes. Granted, not manga and yeah, granted, translations weren't involved. But I also have data points to compare with the otherwise weekly 4 page comic
I take it the tone of my original post didn't come through, which is common in textual communication. I was not complaining, I was not angry. I did not write with malice. It was supposed to be a light commentary on the difference between the otherwise weekly 4 page comic and the extras that seemingly took a considerable longer time
You coming at me like that, even after my second post, without knowing a single thing about me is...rich. You might want to train your reading comprehension a bit more, just like my writing is provably somewhat lacking (see above)
Alright then, from your senpai, I'm going to assume you're just autistic and bad at social cues (and comedy, apparently) and give you some knowledge of the industry, because your current outlook and understanding is woefully inadequate, especially if you're looking to get published.
Writing for volume collections and writing serials are different processes, and can take different lengths, especially if you are the only creator. When you think of weekly releases, you need to think of what is being released and how much work a person can do.
Take Shonen Jump releases, for example. They do weekly releases of around 20 pages per chapters. But each manga have teams of 3-6 people worth working on it as assistants. The main artist is usually just the penciller, and the author is doing the outline or writing, while the assistants work on inking. That means for a 20 page per week release, you're looking at 20 pages of:
-Writer
-Penciller
-Ink
-Letterer
spread across 3-6 people.
Agu-sensei is working on 4 pages a week. However, they do not have assistants as far as I know. Meaning in return for less pages, they need less hands. Approximately 3-6x less hands.
For the volume release, we have 6 new pages that we see, as well as 9 promo art, and 5 cover variants. That's 20 new pages, for different fields, that requires different processes and reviews. So now the workload is 20 pages with added:
-Cover
-Setter
-Writer
-Penciller
-Ink
-Colour
-Letterer
-Promo art
Writing a serial is about consistency, while book publication is about build-up. They do not have the same workflow. A lot of writers who do one-shots, burn out when they get serialized, and serial writers takes a lot of break on book releases, because of the change of workflow.
Basically, the reason your "joke" failed, is because you were wrong.
Source: Me, published author, editor for a lit. magazine, a scanlator, in the industry for 20 years and old as fuck.