To add to this, The whole TDD approach as described in the original book by Kent Beck advocated for throwing away your smaller unit tests after a certain point

To add to this, The whole TDD approach as described in the original book by Kent Beck advocated for throwing away your smaller unit tests after a certain point while keeping the higher level ones. This way you can still be confident in your code on the local level, but you won't get bogged down in the future when you need to do foundational changes. Sometimes I get the feeling that the TDD cargo cult members haven't read the original material.