The argument of the movies watched on digital platforms shorter than the ones in movie theater is true. More precisely it was used to be.
The argument back to 35 mm films that is a film gauge used in film-making and the film standard though they are not common as used to be.
Every movie (35mm) you watch digitally takes less time than you watch in a cinema. Motion pictures, especially old non-digital and filmed movies, are shot and shown at 24 frames per second. However, while these movies are being transferred to video, 25 frames are recorded. That is, there is 1 square difference for every second. The video plays the movie faster, but this is not noticeable for every moment.
Difference can be noticed in the total
There is one second deviation for every 24 seconds while transferring movie to video version. For example, there is a 247.5 second deviation in a 99-minute film, which equals 4 minutes and 8 seconds. This is a sufficient deviation for a 99 -minute movie, which lasts 94 minutes in the video version.
But the argument would not be the case in near future
At the beginning of 2000s, almost all movies shot films. Today, majority of top-grossing movies and other movies are shot on digital cameras. Movies shot on films are losing ground. In following years, there may not be non-digital movies.