Agreed!!!! You have spoken out my mind as well from my 18+ years of dev experience. I do support the concept of having unit-tests (which help in documenting the developer assumptions about the functions expected inputs\outputs, discover missing edge cases and builds confidence when someone else modifies the code for enhancements ) But I do NOT insist on always writing unit-tests before wirintg the core functions. I rather make it a point on trying to achieve 100% unit test coverage via composable unit tests and the permutations pattern , which avoids the bolierplate of things that deter many develpoers from writing unit tests to begin with.

People who insist on the sequence : write tests first and build the functions later ignore the fact that different people have different preferences and just because something works for one person\team in a specific scenario may not work for every developer\team in all development scenarios. TDD may not be even a natural course of action when developers are doing POCs\experimentation\hackathons \building scripts etc when they are onboarding onto a new code-base and trying to get a hang of things.