Many still believe the Earth is flat.
That's the one that's actually making a comeback. I watched an hour-long YouTube video explaining why the Earth was actually flat, with perfectly reasoned arguments that essentially boiled down to "This is a millennia-old conspiracy to con the world into believing something, because..." I've yet to see anyone provide any way anyone could profit from perpetuating the Grand Lie, other than selling globes. And, honestly, what's the margin on those?
Anyway, there are plenty of people who would be totally stoked to find out that magic is real, even with all the terror. I don't know anyone who doesn't have a ghost story, or something similar. I've seen some stuff I can't explain. Personally, I'm reasonably certain that the majority of the population, at least in America, would happily believe that the supernatural exists. It would be too interesting, and, honestly, who wouldn't love watching scientists scramble to explain it?