My assumption is that they're still using a remote backend for state, but they haven't set it up to use the locking features of the backend. For example, I've

My assumption is that they're still using a remote backend for state, but they haven't set it up to use the locking features of the backend. For example, I've use S3 as my Terraform backend for years, but I've never bothered to set up the locking feature, which uses DynamoDB. In a small team that deploys Terraform changes rarely, you may never encounter the problems solved by using locking. Maybe good communication and a Slack channel works well enough for you.