The exact runtime for the upcoming Avengers: Endgame remains unknown at this point in time. Furthermore, it seems safe to say that the exact runtime will remain unknown for some time to come, seeing as how it is traditional for such information to be released once it has received its official rating from the Motion Picture Association of America. Something that won’t be happening until around a month before the theatrical release.
With that said, not knowing the exact runtime isn’t the same as knowing nothing whatsoever about the topic. There are strong indications that Avengers: Endgame could have a 3-hour runtime, with an excellent example being how Joe Russo has outright stated that a rough cut had a runtime that was about that long. As such, while changes will continue to be made in the post-production phase, there is a very high chance that the upcoming movie will have either a 3-hour runtime or something very close to it.
Why Is This the Right Choice of Runtime for the Movie?
There are a lot of people out there who tend to think that a 3-hour runtime for a movie is too long. However, there are excellent reasons to think that a 3-hour runtime is a sound choice for Avengers: Endgame even if it is unsuitable for most movies.
First, Avengers: Endtime is meant to be the climax for the over-arching narrative of the MCU. Yes, Thanos’s first appearance was in the end credits of The Avengers. However, there can be no doubt about the fact that the MCU has focused to a considerable extent on the character’s quest for the Infinity Stones ever since, whether striding about in the foreground or looming in a menacing manner over in the background. Since Avengers: Endtime is supposed to bring a conclusion to that long-running narrative, it is going to need a lot of runtime to tie up a lot of loose ends. Something that is particularly true because there are going to be a ridiculous number of characters showing up in the movie in spite of Thanos’s victory at the end of Avengers: Infinity War.
Second, there is one other issue of importance. In short, the end of the over-arching narrative of the MCU won’t be the end of the MCU. Sure, Thanos is one of the most memorable examples of a Marvel Comics cosmic supervillain, which is why he winded up with becoming the big bad for the MCU so far. However, there are plenty of other contenders as well as plenty of other superheroes to face off against them, meaning that there is more source material that can be mined for MCU movies for years and years to come. However, that won’t be possible unless the proper preparations are made, with Avengers: Endgame being one of the best opportunities to set up the next phase of the shared setting because it will be the biggest crossover movie for some time. In fact, it should be remembered that Disney has now secured the Marvel Comics movie rights that were being held by 21st Century Fox, meaning that the cosmic shenanigans that are bound to come up in Avengers: Endgame will be one of its best chances for incorporating said properties into the MCU.
Combined, these two factors make for a lot of storytelling, which will need a lot of runtime for it to unfold in the proper manner. As a result, a 3-hour runtime isn’t excessive. If anything, it might be too short for something that is supposed to serve as a cap for about a decade’s worth of superhero movies.
Why Is Runtime So Important Anyways?
On a final note, it should be mentioned that Avengers: Endgame has one strength in this regard that most movies can’t hope to match. In short, a long runtime tends to be a bad thing because it makes it that much more difficult for movie-goers to sit through such movies. As a result, a longer movie needs to be able to secure a greater commitment from interested individuals, which means time, attention, and other limited resources. Avengers: Endgame has a huge advantage in this regard because most of the people who are planning to watch it will have already seen at least some of the MCU movies, all of which have been building up to this moment. In other words, chances are good that said individuals are already committed, thus making this less of an issue than under normal circumstances.