Helium embolism can kill people. Due to helium's permeability, it can travel through tissues and into the blood stream. Helium gas bubbles form in the bloodstream, preventing the flow of blood.
https://www.sciencedirect.com/science/article/pii/S134462231...
Divers control the pressure at which the diving gas is being delivered. A person who is breathing helium directly from a tank, either for misguided recreational reasons or with suicidal intent, is unlikely to be doing that.
The original suggestion – of adding helium to a room in order to damage iPhones – unless the room is pressurised, it is going to be at normal atmospheric pressure, so asphyxiation is a far greater risk than embolism. But, the point remains, inhaling helium is actually a lot more risky than many people think, sometimes it kills.
https://www.oregonlive.com/pacific-northwest-news/index.ssf/...
For someone to die using helium, they would literally have to first find pure helium (which isn't sold at party stores any more - helium is mixed with oxygen) and pump it into a plastic bag over their head with the bag sealed (because it will come off when you pass out, you will breath in oxygen, then wake up).