The principles, patterns, and practices chosen to assist with the delivery of software projects are essential to the long term success of the project. Design patterns, development principles, and clean code practices directly impact the quality and speed of delivery of software.
Uncle Bob outlines what he has learned over the years when it comes to architecture on a systems and project level. The goal of architecture is to reduce the long-term cost of a project by delaying decisions and maintaining as much flexibility as possible. A special team does not accomplish this goal but architects who are the best programmers. Through the pragmatic application of principles and architectural methods, one can make a project easier and more cost effective.
The first of the SOLID principles is unfortunately violated quite often even though it is easy to understand why you want to maintain a separation of concerns. It is similar to the SQL injection vulnerabilities that show up on StackOverflow and other places even though the internet is flooded with warnings about how to avoid being pwnd by the easily escapable beast. In the example repository, I give the example of a basketball player that is both a coach and a player.