Helmets today are not what helmets were 20 years ago. I have a size large neck on size medium shoulders from wearing one of the older fiberglass, heavy helmets. My current helmet weighs nothing in comparison and I hardly notice that it is there when pulling "G".
Look up on You-Tube Sean Tucker's talk on his lat bail out. The canopy left a ding in his helmet as it departed despite his hunkering down in his seat to let it go by. A friend was run down and after bailing out found a gouge in his helmet. You can not exit the airplane or deploy your parachute if you are lights out.
As for crashing in an open field and not surviving, without a video record you really can not speculate, but too many pilots appear to lose control of the airplane during an engine failure. All of my friends and acquaintances who kept flying the airplane through touch down, and I am surprised at how many I can count, walked away. And they landed in trees, swamps, some at night. In contrast, a friend just showed me video of a Mooney engine failure during the day in good weather where the pilot never pushed the nose down, tried to turn as the airspeed decayed, and spun in, resulting in a big fireball.
In any case, each of us makes an educated decision of where to spend $$ on safety. Training does not increase the weight of the airplane or pilot. Most other safety gear does, reducing performance.
And if you expect that your airplane is likely to leave you suddenly over hostile landscape, then perhaps it is wise to invest your $$ in making the airplane more reliable.
Best of luck,
Wes
N78PS