At the basic level, this document can serve as a blueprint for groups and leads to establish their bespoke ways of working. I firmly believe that successful development teams have a comprehensive set of best-practices from the very beginning. A solid baseline provides confidence and productivity.
Even without tailoring to your particular situation, these ideas can make software development more efficient and more enjoyable.
The basic principles can guide you when making day to day decisions. You can assess how changes align with the business goals, the social nature of software development, the protection of your team's attention capital and the need for simplicity.
This document promotes a very business-domain centric view of software. Explicitly separating parts of your codebase to follow the business thinking will help with maintainability immensely. Such architecture aligns nicely with the separation of concerns too. Writing and reading your source code will become easier.