A Disruption in the Persistence of Vision for Film Directors

Why Theatrical Film Directors have largely given up the status as Auteurs when working on a Hollywood Studio Movie. 

There has been a seismic shift in our creative arts. In the Neo-Golden Age of TV, the Series Showrunner has become the New Auteur. The Shift has occurred not only because the Auteur in the TV World is the Writer, but also because the artistic influence of the director in Studio Feature films has been on the wane for a while as well. 

Since the early 1970s, the creative visionary in Studio Films has largely been the Director, but that has changed in the last two decades. The shift was slow at first, but it has accelerated over the last seven years. This is due to the studios moving more and more toward becoming Special Entertainment Event promoters, using all their resources to produce and release fewer theatrical films than ever before. Even more restrictive is the creative content the major studios seek when they choose to get behind a film project. The slates for all the Hollywood studios are now completely dominated by big-budget SF… Fantasy… or Supernatural Genre movies, many of which are sequels from Branded Franchises, and with an increasing number of the projects based on comic books as the source material (specifically Marvel and DC). 
This shift has wound up with the typical director on a Hollywood studio production being hired not so much for a unique, artistic vision, but for his ability to fit a filmmaking skill set into creating something much larger than just the mere production of a movie. We’re talking about the creation of an entity so powerful that it is capable of taking over the world — first in Japan on a July weekend, then conquering all of North America the following week. Europe and the rest of Asia are the final targets in the ensuing weeks. The Directors of major studio movie projects are being hired only if they can prove that they have the acumen to handle the production of a movie like a General handle the coordination of many different divisions of troops in tasked to come up victorious in a carefully laid-out campaign of war. 
Unfortunately, the shift of artistic influence does not seem to have helped the Screenwriter(s) working on the average studio film. Unlike what has happened in TV, the screenwriter working in the theatrical film world has traditionally been one of the lowest on the status totem pole when it comes to the creation of a project. And that still appears to be the case in many of the movies that have been produced in last the several years. 
Those who have gained more power are the people who represent the money, whether it is a studio executive, or the executive who represents the company covering the costs of the production. 
The impact of this shift from Director as Auteur to Director as Traffic cop has not necessarily resulted in badly made movies. I speak specifically about the amazing high quality that each Hollywood production continues to showcase such as state of the art technical effects; the highest level of craft on display such as costumes, production design, photography and acting. This has resulted in studio movies maintaining their huge commercial popularity with audiences all over the world. 
The exception to this is North America, where movie attendance has been generally in a slump for several years. Could this slump be attributed to the film director no longer having the same creative voice of other legendary filmmakers in the past? 
The job of a director today often times means sacrificing originality for a vision that matches a largely pre-determined blueprint for the project set up years ago when the property was first born, and/or when the Franchise was bankrolled by the studio.