Well from my personal PoV there are a few problems with that
You can’t detect all credentials reliably, they could be encoded in base64 for example
I think it’s kind of okay to commit credentials and configuration used for the local dev environment (and ONLY the local one). E.g. when you require some infrastructure like a database inside a container for your app. Not every dev wants to manually set a few dozen configuration entries when they quickly want to checkout and run the app