Funny thing is Terraform isn't really cloud agnostic. I don't understand why this keeps coming up as a selling point all the time. Apart from the syntax of HCL and the concept of state-management. You still have to learn each vendors unique resource-types, which is like 10000 times more difficult than the underlying HCL language.
It's still a great product for lots of other reasons, just don't believe for one second it will help you move from AWS to Azure. It's almost like saying YAML is multi-vendor.