I think most people miss the point of TDD. It is not just about edge cases. It ought to be:

* A way of matching requirement use cases to tests.

* to modulate the number of tests written not only to make sure you have enough coverage but also to make sure you don't pointlessly cover the same edge cases multiple times.

* a way to cheaply provide feedback and validation on code as you are writing it.

With AI the ability to churn out useless tests has exploded (both with TDD done badly and with no TDD at all) and that has actually incurred a new type of cost we didnt have to face before.