I get where you’re coming from but this sounds like an insanely bad idea. Perhaps I’d agree with you if there was something like cyanide pills people could opt to take, but even then I’m hesitant. There should be no way for one person (or some subset of people) to decide for everyone that now is the time to die; if someone wants to be in their head and push the limit and die at the last minute, that’s their call and theirs alone. Also, if there is some miraculous rescue but someone has pulled the “instant death” switch, they’ve effectively murdered the rest of the people.