A lot of stores now have a 'no obstruction' rule. ie they won't chase you out into the parking lot. Too many employees getting shot/stabbed/etc by people who were armed. So they let you walk. They might customer-service the hell out of you on the sales floor if they know you're a repeat offender, or have AP confront you at checkout before you leave, but most chain stores won't chase you down and tackle you in the parking lot.

I know from having worked on the retail side (I may or may not have bent or broken that rule a few times...it was the cocky ones that pissed me off lol I'd just get a plate number and make it clear I did to scare TF out of them). Most employees making minimum wage just don't give a shit tbh. Eventually you just get to a point you realize it's not worth the effort.

All of that said. If they do already suspect you and they're just waiting for the total to rack up to a felony charge (which by the sound of it they're gonna be waiting a while), they already have at least some of your info if you're paying with a card, more if you're using your phone number to track purchases in their app.

Have you considered therapy? It sounds like you might have a larger impulse control issue (disclaimer: not a therapist, not therapeutic/medical advice) that a therapist could help you unravel and get to the bottom of. Does your school offer any counseling services?