The article is basically making the point that deploying bits of runtime code, even something as simple as a single purpose cloud function, is unnecessary and makes work. The examples of using StepFunctions (declarative code) and “direct integrations” are given, the latter being the least effort to maintain, but in reality it also hides declarative code inside (e.g. VTL to change the shape of payloads).

The benefit is mainly removing the need to deal with runtimes.