> Why don't cloud providers have a nice way for tools like TF to query the current state of the infra? Maybe they do and I'm doing IaC wrong?

This is technically how Ansible works. Here's an extensive list of modules that deploy resources in various public clouds: https://docs.ansible.com/projects/ansible/2.9/modules/list_o...

That said, it looks like Ansible has deprecated those modules, and that seems fair - I haven't actually heard of anyone deploying infrastructure in a public cloud with Ansible in years. It found its niche is image generation and systems management. Almost all modern tools like Terraform, Pulumi, and even CloudFormation (albeit under the hood) keep a state file.