I'd point out that one of the biggest advantages of Terraform isn't managing cloud infrastructure (though I certainly like it for this), but for providing a common language for integrating vendors and other 3rd parties into my own cloud infrastructure.

I've worked in a couple organizations that had a lot of success managing things like cloud access security brokers, web application firewall appliances, ticketing systems, identity providers (with and without multi-IdP federation) and more.

Doing this without Terraform is incredibly manual and requires even more manual process to keep these systems in sync with your cloud. Having a common automation framework that can manage this is indispensable--and useful even if you're not using Terraform to manage your core infrastructure.