Test in general (unit tests paticularly strongly) are prone to the streetlight effect. The more trivial or unimportant something is, the easier it is to test it

Test in general (unit tests paticularly strongly) are prone to the streetlight effect. The more trivial or unimportant something is, the easier it is to test it. This creates the temptation to test the easy part rather than what's important. And this can be made even worse if the organization pushes for "legibility" via the easy "legible" metrics (e.g line coverage) rather than hard "illegible" metrics (i.e. a review of the tests by an experienced engineer).