The second novel, Authority, focuses on the political maneuvering of those at the Southern Reach organization.
The Southern Reach organization was not portrayed to be nearly as clandestine or manipulative in the film, and watching office politics as a follow-up to a surreal eco-horror film doesn’t feel like the right way to go.
The third novel, Acceptance, returns to Area X during the winter but focuses more on revealing the past of the area.
There are several reasons why the books do not provide a good template for any continuation of the Annihilation franchise.