Null objects and non-nullable types both offer valuable benefits, but they serve different purposes. Null objects encapsulate default behavior, allowing for consistent and reusable handling of missing or default states without repetitive null checks. They integrate seamlessly into polymorphic hierarchies, simplifying code by treating "null" as a valid instance.

Moreover, in domain-driven design, null objects can represent meaningful concepts like a "guest customer" or "default configuration," clarifying intent.