We can make improvements wherever possible: breakaway technology on fences, jumps designed as safely as possible (no false groundlines, tables built with a slight ascent so horses can read the width, etc), thoughtfully maximize safety gear). But there is a point where you are working with an independent thinking creature that weighs 9-10x what you do, and we can only do so much to prepare for the possibilities where horse, rider, and physics collide dangerously. The rest is acknowledging the risk that those possibilities exist and may have permanent consequences. I guess the line is do we accept that acknowledgment that safety precautions have a finite limit and keep going, or stop running cross country at all?
We could make XC a mere flat race across country between flags, and someone would manage to get impaled on one of the flags, or step on the heel of a bell boot and flip over.