Street or dirt, this guy is always with me:
(Garmin inReach mini picture)
No system is perfect, but if you want to mitigate risk then some sort of reliable SOS beacon is a must.
I second this ! And from experience (unfortunately) : keep it in your pocket and not on your bike, because you may be separated in a crash
There is still hope for the rider. In another area where I was living before, they found a motorcycle rider 3 days after the crash in a ditch, alive and well, just with a broken leg. This seems to happen all the time, and the inReach is a solid solution, I can't recommend it enough (I also have a CAT tourniquet and a whistle, all in my left pocket, in addition to the inReach).