The only counter I have to this is that there are some workflows that have test environments, everything can't or shouldn't just run locally. Sometimes these test take time, and instead of babysitting the model to write code and run the build+deploy+test manually, you can send it off to work until the kinks are worked out.

Add to that I have worked on many projects that take more than 20 minutes to fully build and run tests... unfortunately. And I would consider that part of the job of implementing a feature, and to reduce cycles I have to take.

After the "green" signal I will manually review or send off some secondary reviews in other models. Is it wasteful? Probably. But its pretty damn fun (as long as I ignore the elephant in the room.)