I have a lot of history with retail. It is a component of my current job. Shrink is generally down due to better technology in POS systems tracking employees habits and flagging anything weird.. and better camera systems (with some AI) tracking people's movements in a store. Also better cameras mean better positive IDs (licence plates) for the cops to go to an address. Huge metro still has issues, but shrink in general is better today than ever.
In my time working for a large retailer, shrink came more from operational issues than theft. That may have changed since, but probably not by much.