It can lead to inflexible and confusing class design.
Choosing inappropriate fields for a class can result in a design that's hard to maintain or extend. For example, if a `CartItem` class in an e-commerce app only stores a `productId` instead of a `Product` object, it might miss direct access to the product's current price or name, leading to cumbersome code and potential inconsistencies. This weak modeling choice can complicate updates and operations, making the system less robust.