As a pilot in the US, I didn't even realize it was a requirement in other countries to wear high-visibility vests until I flew into Canada and found out I would be required to wear one to do my walk-around inspection of the plane.
Yes the ramp is a busy place, and I suppose it wouldn't hurt for the rampers to wear high-vis clothing. But since I haven't heard about a rash of rampers being run over by planes or baggage carts in the US (with by far the busiest aviation industry in the world) I don't know if it is that important either.
I can tell you I felt pretty silly walking around the plane in my neatly pressed uniform, with a borrowed, smelly, greasy yellow vest on top of it.
One smooth landing is skill. Two in a row is luck. Three in a row and someone is lying.