Why doesn't a typical Axon-based aggregate need a hand-built outbox table?

An Axon-managed event store already behaves like a robust outbox by design. When a command handler calls AggregateLifecycle.apply(), the resulting event is durably stored as part of handling that command, in the same atomic operation, and Axon's own event processors are responsible for reliably delivering that event to every interested listener afterward, including retrying on failure. This is exactly the guarantee a hand-built outbox table and relay process would otherwise need to provide. The situation changes only when code writes to a plain, non-Axon-managed database and separately needs to publish a message through some other channel entirely — at that point Axon's event store isn't involved in the write at all, and the dual-write problem returns, requiring an explicit outbox table to solve.