According to director Joe Russo, the upcoming Avengers 4 movie is not considered to be Marvel's longest-running film ever. Russo said in a recent live interview, "The running time on Avengers 4 is currently sitting right at three hours. We'll see if that holds." Meanwhile, the current Infinity War has 2 hours and 40 minutes is the movie holds the record for the longest time of Marvel.
The film may take a long time because Thanos has accomplished his purpose in the previous movie (Avengers: Infinity War), the Avengers must do something to change everything and save everyone. For the best film transmission, long time for the film is the need. Three hours can be a long time to sit in the movie theater, but with the attractive and glorious Avengers 4 is probably not a big problem.
In post-production work, Russo said the production team had completed 50% of the entire film's work. Currently, the footage is still in the middle of the editing process, Russo also added, "We're really just scratching the surface on our VFX shots. There are more than 3,000 VFX shots in the movie; those require a lot of time and thought and energy and effort, and we're very early in the phase of getting VFX done."
There are a lot of footages that needs to be put into the movie, but for a limited time, filmmakers may have to cut footage. No matter how many footages is reduced, it does not reduce the epic and special aspect of the film. But the fans of this movie should arrange a suitable schedule to go to the theater in order to avoid returning home at sunrise and not be able to work the next day.
Avengers 4 will be released on May 3rd, 2019.