I can't imagine something that catches the plates themselves would be very practical. Rogue sells a strap system for their racks that is a lot nicer on bars than regular pipe safeties, but it has it's disadvantages too.
I believe the IPF does sometimes use spotter arms when benching. This is an IPF rack setup for benching:
Agreed that the rest of the powerlifting world should probably adopt something. I like the EFS benches that have the safety section just to protect the face: