That's not true anymore. Cloudformation supports change sets that you can apply, similar to Terraform. They're not really human readable, but they're there.

They also allow you to manually get out of the UPDATE_ROLLBACK_FAILED state, which was usually where you needed to contact AWS.

Cloudformation also supports Lifecycle events. They are a bit complicated to set up right, but they allow you to tell CloudFormation how to wait and how to proceed in response to resource signals (for instance, the deployment can wait or roll back if new instances in an ASG fail to be deployed). Terraform has none of that. It has "create before destroy", and "depends on", but that's about it AFAIK. If CloudFormation fails it will at least attempt to roll back to a sane state (and usually succeeds). Terraform will give up and leave you to clean up the mess.

Apart from that, Terraform has an advantage because of the modularity, ability to easily bring resources in, reference other resources in remote states etc.