There are two immediate reasons. The first is so that you can manage your secrets and env vars in the same way in development as you do in production. Engineers focus a lot on doing this for code, but this hasn't hit the env var space yet. The second is so that all your secrets live in one place. Doppler is your source of truth for secrets in the same way that GitHub is your source of truth for your code. Your developers pull from GitHub, Azure pulls from GitHub during a deployment, etc. This centralization allows for really smooth access controls and auditing.
But the [Secret Manger](https://cloud.google.com/secret-manager) from google is also easy to use and specially firebase environment config is exactly like the demo. Best wishes ...
We don't think of Secret Manager as a competitor, but more of a destination for your secrets. We have integrations with both AWS and GCP Secrets Manager so you can write directly to them from Doppler.
Hi this is Ruud, founding engineer at Doppler. You can see us as a single source of truth where it is easy to manage your different projects and environments all in 1 place. GCP Secret Manager is great for production, but becomes harder to manage when you want to use it multiple environments with larger teams and in different projects/micro services.