As someone who jumps pretty much only on the hunt field, I didn’t wear a safety vest for the first 50 years I hunted. Then I fell and cracked ribs. For six weeks it HURT to do,well, just about anything. The only advice the MD had for me was “don’t do it again.” --my kids were all 3-day riders (one still is). I always made sure they wore vests when doing o/f. I admit at first I was MORTIFIED that the vest added vastness to my silhouette.
My entire life I’ve taken pride in my slender turn out --that I looked like a potato was not a look I wanted. BUT --I sew --so I altered my hunt attire to fit neatly and properly over my vest. You might ask why I didn’t wear my vest over my hunt clothes instead of under --the view. We fox hunters love tradition – a vest over a coat, stock tie, vest would not be traditional turn out --and I’d need two. I also ride in the summer with my vest on --one big enough to fit over my attire would be too big to wear over a T shirt. Once I had all my clothes correctly tailored --I saw pictures of myself --I look ok --no one can tell I’m wearing a safety vest.
So I’m guessing jump riders don’t wear a vest because they don’t see a need. Once they’ve cracked a rib or two falling on a jump, then tried to do all the house work and farm work with painful rib bones --they may change their minds. I did.