I think I must do cos I have spondylolisthesis in my lumber spine and I haven't had much pain from it since I started doing crunches about 10 years ago. I was originally taught to do them at the gym so hopefully I'm still doing them properly.Do you do your lower back too?
I'm late 40s, I've had two kids but I have a flat stomach and a slightly visible 4-pack* so I'm happy with what I'm doing

*this may have something to do with the gbl I consume.