In short; “The juice is no longer worth the squeeze.” A performance plateau has been reached that requires another set of tools and techniques to deliver beyond the current status quo.
In the competitive business world, innovators are all about increasing juice for the amount of squeeze being applied. Safety has a parallel that goes back 100 years or so from guarding hardware, through observations, policies, procedures, psychology, automation, etc. At each technology plateau there is a lull as the next innovator tries and documents the next squeeze. The other techniques remain in place as a firm foundation. Just like in business, in safety we build on the shoulders of those who have gone before us.
Look for a new squeeze that continues to deliver the zero incident culture juice. For example, form small teams of frontline employees assembled for a short duration to intensely and urgently focus on a needed rapid improvement. If your traditional squeeze has stopped delivering the juice of ever fewer incidents this approach might be the return on investment you successfully implement next as the never-ending squeeze on your time and effort resources continues.