I think you have a very cheap google cloud package. cheaper than AWS.
Cloud9 was purchased over a year ago by Amazon Web Services, and before that they were just a startup that decided to use GCP. Since then, they haven’t migrated c9.io onto AWS simply because they are spending more time making Cloud9 better, regardless of the platform. I’m sure they will migrate their infrastructure at some point, but for now, GCP meets all their needs.