Maybe you're thinking about some specific applications/pieces of code? Probably not a video game?

I think it should be a mix. I disagree with the "extreme minority" portion for most projects. There are times where a manual test is the right answer and there's exploratory manual testing.

Obviously though running through a long sequence of testing manually for every code change is crazy. And some sort of CI setup like you describe is a must for every project this day and age.

Then there's also the question of unit tests vs. system/integration tests...