Comment by brushfoot

It depends. The type of project affects the decision too.

If it's a small, standalone CRUD app on a SQLite database, mocks would probably be a bad option, sure.

On the other hand, it could be an integration platform that integrates with many third-party services. Some of them may not have test environments. Or some of the integrations may be written by third-party contractors, and we can't expose service credentials because of poor permissions granularity. Mocks are a good option there.