I think another reason why "just install a railing" doesn't address the problem if you can't see, you're counting on everyone else realizing the problem and fix

I think another reason why "just install a railing" doesn't address the problem if you can't see, you're counting on everyone else realizing the problem and fixing it with a railing, whereas a head-mounted collision-avoidance system works whether or not anyone else realizes there's a problem. Ideally you'd have "defense in depth" such that your head-mounted collision avoidance system is just a fallback, but honestly it's one of those things where it would be best to take it into your own hands if possible.