Full-contact always implies dangers, hence the need to differentiate it from light sparring or whatever. I once read somewhere that high school wrestling has the highest career-ending injuries of any major sport, at 40 percent. Football was closer to 30.
But I agree head injuries are a far bigger concern than elbow/knee etc. And making striking arts safe tends to make them unrealistic. So grappling sports like Judo are a much better combination of self-defense and safety.