Setting aside the turing completeness of them, in practice Ansible is a complete superset of Terraform. From experience, the only times you appreciate the state file is when you have uncontrolled changes, in which case you are in for a bad time anyway.

Ansible modules are trivial to write and more people should. Most are trivial in practice and just consists of a few underlying API calls. A dozen line snippet you fully understand is generally not a maintenance burden. A couple of thousand someone else wrote might be.