Here's another thing that marks the Hulk as an incredibly difficult character for big screen adaptation, and one that means that the stakes are always lowered. We know that, in the MCU anyway, Bruce Banner is kind of invincible - when he tried to commit suicide once, he transformed into the Hulk and that was that: in his own words, "the big guy spat out the bullet." The Hulk's Superman-like invincibility creates a number of problems. Like Superman, who is constantly berated for his own invincibility by fans and non-fans alike, watching a character who has little to no chance of being killed just isn't that interesting. Even if we know that Marvel aren't going to kill off Iron Man or Captain America, we also like to know that it's a possibility. With the Hulk, constantly faced with the issue of his own invincibility, it becomes kind of boring to watch him at work.