"The GoBeRmEnT Is GoNa TrAcK YoU"
Listen, you got a cell phone, and chances are that's going to give away far, far more than data that your credit card company holds on to.
They're just going to have a line -- "Food Lion, [Date] $88.23" -- not detailed list of your purchases.
Meanwhile if you use a membership card at any sort of grocery store, they absolutely will associate it with you; in many cases you have to register that card with your name and phone in order to use the points. Cash or credit, that's tracking you.
Until modern social media that -- grocery store membership cards -- were one of the best predictors of age, income, gender, etc. available.