That would be a lot of guard rails. It is 277 miles long. And just in the most popular tourist areas, because it has an irregular shape, you are still looking at miles of rails.
It is pretty funny when somebody visits it for the first time, because it’s about a six hour trip from Phoenix, so by the time they get there, they are kind of stiff and fatigued, and in a “it’s just a canyon” attitude.
And then they see it. If you stand behind them, you can sometimes see their legs shake.
And if you really want to see people lose it, go with them on the The Hualapai Tribe Skywalk, where you stand on clear glass and look at a between 500 and 800 foot drop straight down.
It didn’t hit me that way. Back in the day I saw first the North Rim. I sat in wonderment for hours watching the colors change as the sun set. Twenty years ago the family went and mrs_dweller had a reaction like you describe, she couldn’t stand at the rail and look, she had to back off a few feet to keep from swooning
I love the Skywalk. Amazing.