I dislike mocks too; it introduces a lot of duplication that I think is deeply problematic. Automated tests are for me a way to support changing the system easily and safely; lots of mocks often work against that.

But what you're getting is speed. Tests are at their most valuable when they give you quick feedback. As test suite times creep up, people stop running them as much, or at all. I've been on projects where all our tests run in seconds, and it is an enormously different development experience than when they run in minutes.