They can, and they do. Here[1] is a random example of applying that to a supermarket (the other pages on that vendor's site shows some of the other ways the tech can be used).

Solutions tend to use a mix of video camera data and cellular data (wifi and bluetooth beacons[2]) to track in-store movements and behavior.

Done well, they can also connect individual store journeys to specific point of sale transactions, and understand hoe variations of in-store behavioral patterns ultimately influenced actual transactions. Which opens the door to running in-store optimization experiments very similarly to how you'd run A/B optimization tests for websites/apps.

[1] https://retailerin.com/en/retailerINfor/customer-behaviour-a...

[2] https://www.thinkwithgoogle.com/marketing-resources/retail-m...