Shops without roles usually share one login, which means the audit trail is worthless. If every action is recorded under the same account, you can see that a refund happened but never who did it.
The point is not distrust — it is clarity. Separate logins protect honest staff as much as they deter dishonest ones, because a specific person can be cleared as easily as identified.
Sensitive actions worth restricting are the ones that move money or hide it: refunds, voids, discounts above a threshold, stock write-offs, and price edits.
Outale ships roles for Cashier, Manager, Inventory Manager, Viewer and Accountant, with PIN login per employee, a PIN gate before sensitive actions, and audit logs that carry the staff name.