The fact that you think "change detection" tests offer zero value speaks volumes. Those may well be the most important use of unit tests. Getting the function correct in the first place isn't that hard for a senior developer, which is often why it's tempting to skip unit tests. But then you go refactor something and oops you broke it without realizing it, some boring obvious edge case, or the like.
These tests are also very time consuming to write, with lots of boilerplate that AI is very good at writing.
>The fact that you think "change detection" tests offer zero value speaks volumes.
But code should change. What shouldn't change, if business rules don't change, is APIs and contracts. And for that we have integration tests and end to end tests.
These tests are also very time consuming to write, with lots of boilerplate that AI is very good at writing.