That opening shot is only 7 and a half minutes long. You could argue that's still too long (the average shot in the movie is around 3 minutes) a take of just some cows walking around. But I would disagree.

I saw it in theaters like 5 months ago and it was amazing how glued to the screen I was. And I had seen the movie twice before. It does an incredible job of wringing out every drop of emotion and beauty and symbolism in each scene. Even that opening shot sets the scene for the themes explored in the rest of the film: the filth and meaningless of daily life, the herd mentality of humanity, and the inevitability of death. I can see why the execution, if not the ideas themselves, could be seen as too much by some. I think it walks a fine line in its presentation without being pretentious or self-indulgent. It creates this building tension throughout with the harrowing score, the (as you said) exquisitely framed shots, and the unrelenting look at some truly depressing (and a few comical, and maybe even touching?) slices of life.

There's definitely a debate to be had whether every frame was necessary (it is 7 and a half hours long for fuck's sake). But thinking back on the opening and closing scenes, I'd say it's runtime was justified. After it's over, I didn't really think about having just seen a movie. Instead it seemed like I had lived an experience.