As someone who spends time writing about Lois Lane, Pepper Potts, and Jane Foster’s incarnations of the leading ladies of comic book characters on film, immediately I latched onto Liv Tyler’s version of Betty Ross while doing our scholarly viewing (as I am sure you suspected I would). The center of the film is their love story, built from the opening backstory of Bruce Banner’s accident in the montage opening sequence. So why, then, is she absent through the rest of the MCU? In 2018, the Russo brothers explain what happened to Betty—she died in the snap. At the time, many predicted she would return in Avengers 4, aka Endgame (Bacon, https://screenrant.com/infinity-war-aunt-may-betty-ross-lady-sif-fate/). However, we now know that she didn’t. Poor Bruce was left without Betty or the misguided Whedon twist of would-they-or-won’t-they love interest of Nat, otherwise known as doomed heroine the Black Widow. Barring Liv Tyler as an actress not wanting to reprise the role—I mean, they recast everyone else? Why not recast Betty if that was the case?—what happened to Betty?
In The Incredible Hulk, Banner and Ross' romance was structured more poignantly than I had remembered. And I readily admit that this was the one film I had not been excited to re-watch. I’m not sure why, but I had seen parts once or twice on television, but I can’t remember seeing it fully at the theater. Perhaps I did, but it was so not-memorable that I can’t pinpoint if I did or didn’t. Again, I wonder why.
At the time, I don’t know if I even knew there was an end-credit scene, now a must for the MCU. Even Endgame had the touching sound of Tony Stark hammering his helmet as a tribute, though it didn’t have a specific scene as the movie was the marker for the end of the phase. Many on Quora have remarked that one reason why Betty isn’t present in the MCU later is that she “was a calming factor” to Banner, and that would interfere with the whole idea of the Hulk’s rage. Others pinpoint that it would interfere with the Black Widow-Bruce Banner pairing, and others just say she was not needed (https://www.quora.com/Why-dont-we-see-Betty-Ross-in-the-MCU-anymore-after-Liv-Tyler-s-performance).
What I think the series loses here is something interesting outside of The Incredible Hulk. Natasha Romanoff is not a love interest; she is an Avenger in her own right. By pairing Bruce and Natasha instead of Bruce and Betty, it limits her viability outside of being just there for Bruce to pine over or, as in Age of Ultron, to have dramatic angst over a relationship that won’t work (that is worthy of a soap opera in itself). Side note: Let’s hope that is corrected in the postponed Black Widow.
In short, Betty had a large role in this film, and she is prevalent in most every incarnation of the Hulk in some way, much like Pepper Potts or Jane Foster. It may change shape depending on the comic’s thread or a different “universe.” But there was nothing wrong with Liv Tyler’s Betty—and I still can’t figure out why I forgot about this movie. She has agency, and she makes her own choices about her life outside of the love interest facet. In some ways, she even saves both Bruce and the Hulk, taking control when she needs to help them survive the night or find shelter. In addition, there is a real punch to the last act, as she confronts her father and worries over Bruce potentially sacrificing himself in New York. That major action scene is referenced later in the first Avengers. So despite a few nods here and there, sadly, we lost out on a normal, non-super powered character who could have added layers to the subsequent storylines—and added emotional value to Bruce Banner who, himself, sometimes appears as a one-note sidekick there to help the other Avengers or move the story forward.
According to Hood’s 2019 article for ScreenRant, Liv Tyler’s Betty might show up in the Disney+ long-anticipated series She-Hulk (https://screenrant.com/she-hulk-betty-ross-liv-tyler-return-rumor/). I think that would be a great return for a forgotten character who had promise. Do I need to start a hashtag #BringBackBetty? Maybe! Anyone want to join me? Let’s start a trend. I mean, hey, it worked for Zack Snyder’s Justice League!