Step Functions has a maximum number of history events of 25,000. This means if you have a data set with thousands of entries in it, you might exceed the limit of state transitions. You might also run into the data size limit as well for sets that large.

Configuration with the Amazon States Language Amazon States Language is quite complex; its syntax is based on JSON and therefore optimized for machine readability instead of readability by humans.

Decoupling business logic from task sequencing can make your code harder to understand While decoupling services from the orchestration layer can make things more scalable and easier to operate

Vendor lock-in The Amazon States Language is proprietary and can only be used on AWS.

https://docs.aws.amazon.com/step-functions/latest/dg/connect-to-resource.html