You order your day by need, not recent memory
Before, you treated whatever stuck in your head last as most urgent, even when it wasn't, and let older items get lost. With the three fixed spots checked at opening, stalled chats, open orders, low stock, the order now comes from what needs action today, written in a note, not from whatever you remembered last.
You catch pending items before delay turns them into problems
Without a fixed check, you only noticed what you'd forgotten once it had become a bigger problem: the customer gave up, the delivery ran late, the product ran out. By looking at the three spots every morning, the store handles what needs action before that delay grows.
You start the day with direction, not reaction
Before, you let whatever shouted loudest pull your attention, a message, a phone call, a customer at the door, even when it wasn't the most urgent one. With the order based on what needs action today, the store decides where to start instead of responding to whatever arrived first.
You keep every pending item visible instead of only in your head
When you keep everything only in the memory of whoever helped the customer, no one else can tell what's still pending. With the check's note written and numbered, the pending item and the order to act stay visible to whoever needs to keep the service going, without having to ask whoever remembers.