It's an obsession with some people.
As for me, I have every James A. Michener book ever written in my library and I've only read a few. Hawaii, Texas, Alaska, Space and Source. All the others I have not yet read. Is it worth reading the others? I do not know. I'm rather tired of Michener's writing formula.
If you like Mitchner you’ll enjoy this book, https://en.wikipedia.org/wiki/A_Land_Remembered.
I’ve read it twice.