> On terraform it's different, because of the tfstate. All the deployed elements are stored in the tfstate, re-running terraform won't update resources that are supposed to be in a specific state but are not.

This is incorrect, and makes me wonder how the author has used terraform. Terraform will certainly detect differences between managed and current state for the resources it manages whenever you do a plan/apply.

The major challenge is that terraform _can only reconcile resources or configuration values it knows about_, and that depends very much on how a particular cloud vendor or terraform provider has modelled resources. I believe the Helm provider is one example where it (at least in the past) haven't had a good way to reconcile state.