Ant-Man 3 and Avengers 4 certainly have some key elements in common when looking at them from a broad perspective, most notably considering that both of them deal heavily with the Quantum Realm. Ant-Man and the Avengers use this world in an effort to collect the Infinity Stones in Endgame and save half of humanity before Scott Lang and his family end up sucked into the world for the vast majority of Ant-Man 3's story.
One of those was the end of the story, which saw Scott Lang and Hope Van Dyne not only defeat Kang in the Quantum Realm but escape back to the real world and get their "happily ever after"-style ending instead of dealing with something much worse.
Ant-Man 3 Avoiding Avengers: Endgame Comparisons
Speaking with The Hollywood Reporter, Ant-Man and The Wasp: Quantumania writer Jeff Loveness opened up about how he and Marvel Studios' filmmakers removed the original ending of the movie and replaced it, in order to to avoid repeating a story beat from 2019's Avengers: Endgame.
When asked about whether there was ever an ending where Scott and Hope were stuck in the Quantum Realm, Loveness explained that this would "literally be copying the exact same beat" from the final moments of Ant-Man and the Wasp.
This would have forced Scott to use the same tactics he used in Avengers: Endgame in order to escape the Quantum Realm again, making the movies too similar:
"Yeah, absolutely. That was all stuff we debated, and on paper, it seemed thrilling. But at the end of the day, we’d literally be copying the exact same beat from the end of the last 'Ant-Man' movie. There also weren’t a lot of ways to go that were different from 'Endgame.' If Scott gets trapped in the Quantum Realm like he does in the last movie’s ending, then the only way to go is that he gets out of the Quantum Realm like he does in 'Endgame.'"
This led to the removal of the original version of the movie's ending, with reshoots just before Quantumania was released reportedly enabling the final moments to be retooled.
Loveness described Scott Lang as "a man who’s been through constant pain, loss and sorrow," explaining that it may actually be more surprising to see him get a happy ending like the one he got in Ant-Man 3:
"Scott Lang, much like Spider-Man or Charlie Brown, is a man who’s been through constant pain, loss and sorrow. And so the more unexpected thing would be to maybe give him a happy ending, but with the lack of assurance that he has in the first act. There’s this ever-gnawing sense of dread in him, whereas at the top of the movie, he’s carefree while his family are keeping secrets from him. And now we end the movie with his family carefree, but he has this secret that he’s keeping. He has this feeling of approaching dread, and he’s choosing to bury that terrible sinking feeling that’s coming for him."
Loveness also spoke with Variety about the movie's ending, reconfirming both that there were discussions about having Scott and Hope stuck in the Quantum Realm but also expressing uncertainty that it "would have been satisfying" to see that again:
"It was certainly discussed. I don’t know if I’m allowed to discuss that. As we got close to production, we certainly went through every beat of that and thought of which ways to go. [Staying behind] to me feels a little repetitive. I don’t know if that would have been satisfying. That feels a little reductive to the second movie, like oh, they’re just trapped again and they’ll get out in the next 'Endgame' or something. It would have not been as good if we repeated the beats of the second movie."
Gizmondo also spoke with Loveness about Ant-Man 3's ending, where he called it "cooler" to have such a worry-free character actually end his story on a high note, comparing it to Frodo in Lord of the Rings. While he had the adventure, Scott also has the looming feeling that he may have screwed up, making it so that the man that saved the universe in the Infinity Saga may be the one that screws everything up in the Multiverse Saga:
"I think it’s actually cooler to have the guy who was so carefree and who thought his heroic days were behind him now ends the movie like Frodo coming back to the Shire. You had your adventure, but you’re not the same guy anymore. You don’t have that ease of mind. And as much as you want to eat that cake and try to give your daughter that fake birthday, you know that maybe you messed up. I think a compelling thing is that the guy who quite literally saved the universe in the last Phase might accidentally be the guy who fucks up the Multiverse in this Phase. Like, let’s see in the future. We’ll see what happens, man."
No Quantum Realm Troubles for Ant-Man 3
Ant-Man 3 certainly went through a few different options for how the movie was going to finish, with reshoots taking place only a month before its release to make sure the story had the effect that Marvel was looking for.
Largely, this was to ensure that Marvel wasn't repeating itself with story beats, especially considering how many complaints Marvel has dealt with across the board over the past couple of years.
For now, fans will have to wait a little longer to see how dangerous Kang will be as the Multiverse Saga moves forward, although Ant-Man 3's second post-credits scene already teased that more of this will come in Loki Season 2. And with this threequel serving as an immediate setup for Avengers: The Kang Dynasty and other upcoming movies, new dangers aren't far off even after a relatively happy ending this time around.
Ant-Man and The Wasp: Quantumania is now playing in theaters worldwide.