Hi Sri Krishna,
The goal of the Firebase token was to allow the CLI to impersonate you without going through a sign in flow so the CLI could be used in CI/CD type workflows. A service account enables similar use cases but in a more secure and less disruptive manner.
If the Firebase token was sufficient for your use case then a service account should be a drop in replacement.
Using an organization structure will provide additional environment/user/team management features but those are not necessary to replicate the functionality provided by the Firebase token.
Hope this helps,
Arthur.