I think you are agreeing with me. There's anecdotal evidence like you offer. It's not necessarily obvious to everyone that automated tests improve code quality

I think you are agreeing with me. There's anecdotal evidence like you offer. It's not necessarily obvious to everyone that automated tests improve code quality or it would be a settled issue (it's not). In my own career (40+ years) I have worked with automated testing and TDD, and without, and I can't say that TDD "obviously" improves code quality. I know other professional programmers who have that experience. Like everything else in software development it's probably situational and depends on the individuals and the team.