The send port already sits at the exact boundary where the outside world can fail, and it already knows how to retry, slow down and set aside. When you let it do that job, every destination inherits the same observable, tunable behaviour for free, and the failure stays where it happened — on the way out — instead of leaking back into the receive transaction.

Hand-rolling this in code is worse on every axis. A retry loop inside a component holds the inbound transaction open, hides its state from tracking, and has to be re-tested for every integration that copies it. The port’s settings are declarative, visible in one place, and consistent across the whole platform. The mechanics of each piece live in the retry, throttling and dead-letter patterns.