I guess it was your agreement with the tinfoil hat "It's a bit scary when all your purchases can be monitored". If the purchase of (for example) toilet paper being "monitored" is "scary", I'd say that person has much deeper psychological issues
Method of payment makes no difference. "They" know everything about you. Where do you get cash? Oh that's right, from an ATM, which photographs you withdrawing the cash.
Reassuring you that "they" are watching you, no matter how much you try to hide. They have your facial biometrics and your fingerprints. You are being watched
QR code is really king in Thailand. No need to carry large sums of cash, accepted universally - almost impossible to find anyone NOT accepting QR code. It's brilliant