This is a repository containing some GCP Terraform examples. They are just examples and might help you in specific topics. Not more. Its your responsibility to check for flaws or issues. Its also likely that this examples might be outdated when you use it.
The examples might also use external modules provided by someone else to simplify the example and not blow it up with complex code. Modules are a good think and I can only encourage you to have a look at modules if you are not using them yet.