I had this happen many years ago, left my purse sitting in front part
of grocery shopping cart, bent down to lift laundry detergent, and then my purse was gone.
I ran through the store, no purse snatcher was seen.
Takeaway - Never let your purse out of sight.
Apparently I had a thief watching me while shopping. Creepy
Also I've used a cross body since.
Love the Baggallini brand has anti-theft components, designed for travelers.
I find them at Marshalls & TJ Max, and last for years.