Imagine when we get the first interstellar ships. Even if 90% of them blow up at launch, it'd still be, by far, the 'safest' method of transit in existence if we use the deaths/mile stat.

Even for planes the stat is deceptive. Most people, hearing about the safety of flight, would think that if they replaced their car with a plane then they'd be far less likely to die in a crash, but that would be untrue because the real risk in flight is take off and landing - the distance traveled is near irrelevant.