Fake Authors?

I illustrated a graphic novel that my dad wrote.  It was a true collaboration as we respected each others talents and acted accordingly.  The graphic novel took me roughly ten years to finish, one year to find a publisher, and currently on-going years to market it.  I put my heart and soul into it.  I also learned a lot about making books.  Being in average physical condition and my health relatively normal, and often working 12 hour days sometimes, why did it take me ten years and not one year?  Isn't one or two years to finish a book the average duration of the New York Times best selling authors?  And why do they all have 30, 40, or even 50 books out?  Not to mention all the interviews they do and podcasts and youtube videos?

The math doesn't add up!

To name a few authors:

John Michael Greer has published 42 books.  Ok, that's a lot, but not impossible.
Danielle Steel - over 100 books.  Ok, I'm pretty sure that's impossible.
Stephen King - over 100 books.  Impossible.
James Paterson - on his way to 1,000.  Terribly impossible! just check out his bibliography - https://www.fantasticfiction.com/p/james-patterson/
but be prepared to scroll for a while

Do these people not eat, sleep, or go out for supplies like toilet paper?  Not to mention they also have hundreds of interviews to do and conventions to go to and youtube videos to be on.  Again the math doesn't make sense.

I know what it takes to make an authentic and legitimate book with meaning and quality.  I know how much it takes out of a person.  I know I have other things to do in life then work on the book.  So how do they do it?  Speculations broaden much... from these authors not being human, to secret technology that can create a book with a few keyboard commands (like a plot generator but more powerful) called evolutionary computation, and to some distorted magic or evil spiritual power.

The mystery is not only reserved for authors; directors, athletes, and artists are all achieving extraordinary feats with little actual work and seemingly spiting time in the process.