In your experience how often have you had template builds succeed but then fail at apply time? This kind of issue is what I find most frustrating about IaC today, your 'code' 'compiling' means nothing because all of the validations are serverside, and sometimes you won't find out something's wrong until Terraform is already half done applying. I want to be able to declare my infrastructure, be able to fully validate it offline, and have it work first try when I apply it.
I find Pulumi very nice here because it persists state after every successful resource creation. If it breaks somewhere in the middle, the next run will just pick up where it left off last time.
CDK… well, CDK doesn’t get in an invalid state often either, but that’s because it spends 30m rolling back every time something goes wrong.
