Central, top-down architecture is extremely political. You have to fight with bigwigs who don't know your problem domain and don't live in your codebase to make it reasonable, or even possible, to solve the business problems on your plate when they inevitably don't fit the 10,000 foot 5-year plan.
Pushing down architecture responsibilities into the hands of senior engineers with specific problems to solve / features to build eliminates that form of politics. They are not disguised architects, because designing the architecture is only phase of the project. They also have to live with the architecture. This is a great thing.
architecture is political because an architecture (or a system) always ends up mirroring the organization that produced/operates it. A well-known fact in OB, and one reason why one wants to engineer (i.e. architect) the organization simultaneously with the system, otherwise you create silos or disjoint systems that can't talk to each other.
Pushing down architecture responsibilities into the hands of senior engineers with specific problems to solve / features to build eliminates that form of politics. They are not disguised architects, because designing the architecture is only phase of the project. They also have to live with the architecture. This is a great thing.