I think this is poor advice because it doesn't give context. I think unit tests are good for testing logic, and integration tests are good for testing function

I think this is poor advice because it doesn't give context. I think unit tests are good for testing logic, and integration tests are good for testing functionality. Lots of complex logic? Then write lots of unit tests. Got a service that just wraps a database? Then you're going to want to write a lot of integration tests.