How to Tell a CTO Your Code Is Hard for the Team to Work With

Most people in engineering management do not know how to do it because they were there early. They've never seen good management. I could see this as a mistake caused by lack of management experience either directly or having been modeled to the CTO. The term I would put on that is unsustainable. But just just the CTO getting defensive and saying like, you can't change my code. It's the best. Well, he kind of said that he says in the question, he gets angry and tells us that we're not focused on delivering a finished product. Like is he right when he says that? I don't know. Obviously, we don't.