> When I test my code, I want to know that it works in production. Staging, you can’t give me that.

This sounds like more of a problem with the author's staging environment than a general issue with the concept of staging environments.

The idea is staging and production should mirror eachother as closely as possible. If your staging environment is wildly different, of course it will be less useful. But it's also your responsibility to maintain a useful-enough staging environment. Why not just say, "it's too much effort for me to maintain a separate, identical environment" rather than dismiss the concept entirely?