I already have all the prevention I need between my ears to prevent me from standing 25 feet upstream of a large water fall.
Larger guardrails and more signs would only delay, not prevent the eventual early demise of people willing to do this.
Even the most ‘experienced’ hikers, climbers, explorers still die on easy hikes, common sense or not. I guess common sense should tell you to stay home, but then you’ll die of a heart attack, stroke, cancer, whatever.