According to Wordcounter.net:
– 1 page is 500 words single spaced, 250 words double spaced, and
– 80 pages is 40,000 words single spaced; 20,000 words double spaced.

So, in order to write a good-sized book, you just have to write 500 a day for 80 days.
You do not have to write 500 good words either. There are plenty of horrible books with many more pages than 80.
But if you have a desire to write a book, the first step is to write enough pages.
It’s not as challenging or time-consuming as you think.
By the way, this is only 100 words.
Do you want to write a book? Are you writing 500 words as day? Email me at jclevelandpayne@gmail.com, and we can discuss.