What is something that people think is dangerous but in reality is completely harmless?

Why did I read that like the Pokérap

Studies showed that MSG is entirely safe and only that some people may have "sensitivity" to it, akin to caffeine or any other food sensitivity. (note this is not allergy)

I've always wanted to try mixing my Bugles with a dusting of MSG, it could be so tasty!

2.4ghz WiFi is actually classed as a carcinogen by the WHO. There's some pretty interesting and heavily peer reviewed research supporting this. https://www.tandfonline.com/doi/full/10.1080/10643389.2021.1951549