Its to prevent violence in my opinion. Almost noone there is permitted to confront anyone. The loss prevention person assigned to the store rotates, and is only there maybe once every few weeks.
All of that means it takes years for them to case build enough to get police involved, at least in certain areas. Covid also made it normal to disguise yourself, which is far easier to argue against than a full face video, even with their video quality being shit.
They have an kroger message board for employees and you can read what their LP employees talk about there. Kind of odd how all that works.