While I certainly found it insightful, I felt like this book (like so many in the genre) was a pamphlet's worth of material inflated to fill about 250 pages.
It's true that you can boil it down a lot. In fact, the book even has a checklist checklist that distills down the advice to one page. However it was overall a very quick read and the extra discussion really did further my understanding of the underlying principles that make a checklist good. I'd recommend reading the whole thing so that you actually make a useful checklist instead of a cargo-cult copy of an aviation checklist.
[1] https://atulgawande.com/book/the-checklist-manifesto/