I take it you've not heard of
Euro Ncap . They rate cars not just on their abilities to protect the occupants, but also how pedestrians fare when run over by one.
The sad fact is for all of the changes and improvements in car design safety, if you get run over by a car at 40 or 50, then the odds of you surviving are substantially less than at 30 or 20. If one does wear a piece of clothing to help drivers see them earlier, then that translates into reaction and braking time which will in turn reduce the risk of injury, or indeed the severity of the injury itself.
I sustained a life changing injury as a pillion on a PTW when I was 17 (riders fault) and spent the best part of 6 months on crutches, and I can happily testify that prevention is far more valuable than any compensation payout. ..that is ultimately what the high vz and reflective is looking to achieve.
(no legal training, just some dealings with RTAs and the legal system over the years).