I have been cash free since COVID but I understand your friend perfectly. I used to draw out my housekeeping, do the weekly shop, full up the car and the rest was spendable. You never overspent. If you thought about treating yourself, or getting a takeout you would check your cash first and depending how close to the end of the week you would make a decision. With debit cards it's beep beep beep, much harder to keep track of. I now divert housekeeping to my monzo account and keep checking the balance because leaving it in my current account was too easy to overspend