I figured it was an effect of the curse as well, not that Emma has to believe to sustain the worlds.
ALTHOUGH: I have always thought that magic and the multiple story realms were dependent on the beliefs of the people in our world. I had a thread back in the day about that, I think. But I basically said that since we know magic runs on belief, in order for magic to exist and therefore magical worlds, the stories have to be told here so we can believe and thus power those worlds and keep them alive. If we stop beliving they’d die (which was kinda similar to what occurred in Neverland. The magic was running out and so Neverland was dying.) So that makes sense.
"I could have the giant duck as my steed!" --Daniel Radcliffe
Keeper Of Tamara's Taser , Jafar's Staff, Kitsis’s Glasses , Ariel’s Tail, Dopey's Hat , Peter Pan’s Shadow, Outfit, & Pied Cloak,Red Queen's Castle, White Rabbit's Power To World Hop, Zelena's BroomStick, & ALL MAGIC