I think @maxim will have a lot to say here as well so I’m tagging him. While StepFunctions and Temporal may look very similar in the problems they aim to solve they are completely different classes of solution.
You’re right in noticing that StepFunctions provides some guarantees around reliability and consistency that are comparable to Temporal, but that’s where the similarities end. Temporal enables you to implement business logic with pure code. This is one of the biggest (if not the biggest) differentiators between Temporal and any other solution on the market. When I talk to users who have switched from another solution to Temporal, this is the number one reason I hear. Keep in mind that this isn’t just a matter of preference. Many users migrated from StepFunctions because it was not suited for applications of even moderate complexity. This is because the JSON based system that StepFunctions offers cannot efficiently express complex logic.
Outside of this fundamental limitation, there are countless features and capabilities (such as Visibility) API that Temporal offers but StepFunctions does not. It’s also important to note that Temporal is open source and StepFunctions is not, so testing locally will never be as reliable with StepFunctions.
It seems like your biggest hesitation with Temporal is having to host it yourself. Short term we are more than happy to guide you through process of setting up Temporal for your use case. Longer term, we are actively working on a hosted offering which should be available in the relatively near future.