terraform 'destroy' isn't infallible. There are certain resources that trigger the creation of other resources (for example, lambda functions will create cloudwatch log groups, and dynamodb tables create cloudwatch alarms) and when terraform destroys the resource, it doesn't necessarily clean up all the associated resources.
Terraform has it's shortcomings for sure, but I don't think it's reasonable to expect Terraform to go out and clean up second-order effects of it's resources.
I'm not doubting that the situations you describe are true, but abandoning resources like that is an AWS-lifecycle problem, not really a Terraform one.
Sure. My point is just that `terraform destroy` doesn't necessarily solve the problem at hand. And you could still end up continue paying for those second-order effects after running a terraform destroy.
I am pretty senior and can thus sometimes afford to do a new thing and try doing it the right way, at the same time. Not even always. Many people just take one learning curve at a time...
Typically Terraform takes longer to get something working than mindlessly clicking through the console. In my experience those mindless clickthrough things end up sticking around for years even when they weren't intended to.
This is why you have separate development and production accounts: a development account where you mindlessly click through so that you can learn through the UI what's available and how it works; cleaned up on a regular basis by something like aws-nuke, and a production account where you have the discipline to only create resources through Terraform / CloudFormation etc.
I know it’s rhetorical and a lesson learned myself, but yeah… I would expect folks to learn to use this tool to help manage costs this way.