More and more screenwriting experts are claiming that 3-Act Structure is dead, and/or that the original Field-inspired paradigm is no longer valid. Rumors of the 3-Act Structure's demise have been greatly exaggerated. But the way the paradigm is being implemented in many mainstream blockbusters has changed, indubitably.
Unfortunately this change is not resulting in better storytelling. Quite the contrary.
What's happening nowadays? Films, on average, are shorter than say ten years ago. They used to be 120 minutes, while now 100 minutes seems to be the new norm.
This change in length means that the original distribution of major turning points (all together now: end of Act 1 page 30, midpoint page 60, end of Act 2 p. 90, focus points on pages 45 and 75, thirty pages for your third act which includes the crisis, its aftermath and the climax and resolution) is no longer valid. As we're now working with 100 instead of 120 pages.
However, act 1 still takes 30 pages. The midpoint, which should now be around page 50, is still firmly ensconced on page 60. Focus point 2 (which coincides with the Dark Night Of The Soul-segment from the Save The Cat-model) is still at page 75.
But that's when things start to give way.
The third act is of necessity shorter than it used to be. Which is fairly weird because this is where we want to provide the biggest oomphs, the most powerful emotional impact, the most riveting revelations. Yet there's simply not enough time to actually give these essential elements their due.
The second half of act two has also been truncated. You no longer have the 'luxury' of 15 pages to take you from page 75 to the act break. So you're forced to compress your storytelling so you can get to the act 2 break quicker (I would guesstimate that the break now often falls between page 80 to 85). Which means your entire Act 2 climax needs to be rushed.
The problem we see more and more nowadays is that writers tell more than half of their story at the 'traditional' pace, intended to provide enough story material for a two-hour film. And then they have to rush through what should be the most impressive and memorable parts of the script(and the film) in order to get everything finished on time.
The saddest thing is that this changing structure is not something discovered and developed by writers in order to improve the quality of their storytelling. It's mandated by economic concerns - shorter movies mean more showings a day and thus more dollars flowing in per diem.
If you want to see this structure in action, watch Thor (2011). End of act One (exactly after thirty minutes): Thor is banished from Asgard and stripped of his might by Odin. Midpoint (60 minutes): Thor gets his hands on his hammer, but he hasn't yet learned his lesson, and remains powerless. Focus point 2: Thor's Asgardian friends reach him on Earth but his evil brother Loki sends The Destroyer to kill Thor. And then, things get hazy - Thor dies, Thor is resurrected, defeats The Destroyer, zips back to Asgard to defeat Loki and stop his utterly pointless Evil Plan, reunites with his father, and mourns the loss of his whiny Midgard-bound lady love Jane Foster - all in roughly twenty minutes. Which in practice means that none of the Big Moments have any real impact on the viewer, because there's not enough time to set them up and to have them resound with the audience.
Perhaps we should redraw the Post-Field Paradigm (Field's paradigm augmented with various and sundry elements from other major dramatic writing theorists) so that it now consists of two thirty minute acts, and two twenty minute acts (and yes, this would kill the three-act model if it were to become dominant in the marketplace). Or, perhaps, a 30 minute first act, a 40 minute second act and a 30 minute third act to cap things off. Which means that the middle of the story would lose importance, and story density would inevitably be reduced. But structural points could be redistributed in such a way that this new paradigm might start to deliver satisfactory screen stories on a regular basis.
Or we could just go for a 25/50/25-page 3-act model instead of a 30/60/30-page one, and keep everything as it is. Only told faster.
For the moment, everything is up in the air. Until the next guru comes along...