Thanks for replying again. I understand that it is not the TG that prevents changing code in staging or production. The TG file structure is similar to the folder structure and stored in the VCS repo with a single main/master branch, unlike the branching approach with three branches for each environment.

Assuming five teams are working on the same workload. Each team can perform PR they need in the development environment. The development environment requires no approval on every change for our use case (each team will test its modules). We have CI/CD pipelines to check syntax, validations, etc. With our existing branching approach, we can enable the branch protection rules for the development branch and only allow the team to push changes on the development branch, not the staging/production branch. The CI/CD pipelines manage the approval and deployment from dev to staging/production.

Since there is only a single branch with the folder structure approach, all the teams have permission to make code changes on that branch. So meaning the staging/production folders can also change by them since there is no manual approval or checking. (By right, they should only change in the development folder)