Whether it will ever actually save your life is another matter but think of the saving
Its very doubtful they have saved anyone's life. And if they really were about safety on air ports they would be made out of something that doesn't melt and implant itself into your skin when it gets hot.
All the incidents I have read up about both wearing and not wearing a hi-viz the reason for the incident was the piece of machinery wasn't under control.
Plus also these days everything is high viz so the effect is lost. I would wear one on a road if the car broke down. Because it contrasts with the surroundings. Airside the effect has now gone. And there is just a ratcheting off requirements after every incident. First it was the jacket, then it was the ttrouser's, then the caps were mandating. What's next everyone has to wear a beacon on there heads and a couple of strobes on there shoulders.