I just realized something tragic

The sole reason Betty stays behind to make her wish to banish Golb is because she doesn’t want to risk the crown reverting from its prime wishing state once they leave his stomach. But after discovering that wishing to banish Golb is too powerful a wish to grant and sacrifices herself in exchange for keeping Simon safe, Gunther picks up the crown, puts it on, and takes on the form of the ice thing, granting his wish of being like the Ice King. If Betty had escaped with Simon and Finn, the crown would have still worked. Even if it still couldn’t grant her wish of banishing Golb, she likely would have managed to come up with SOMETHING that didn’t end up sacrificing herself