When I broke into the business back in the Paleolithic era (1987), the rule of thumb was 2 pages per scene. Now I tell my students, 1 1/2 pages. Can there be 3, 4, 5 page scenes. Sure. But anything over 1 1/2 pages, they have to *justify* that length.
I think a lot of this has to do with digital technology. For the last three decades, digital filmmaking allows for super easy editing. No longer cutting on film, we have grown use to cut/cut/cut/cut. Plus, audiences today need less exposition. So what used to be the end of Act One in the 80s is now the middle of Act One. Get. The. Story. Moving.
I always used to try to land my feature scripts on P. 112 because that was how long the K-9 spec script was. My good luck charm. Now, I aim for 105, like almost every other screenwriter I know.