It's really about granularity - when I'm building something there are parts of the system where I want very fine-grained control and oversight over what is built and how, and there are others where... it just doesn't really matter. What matters to who is contextual - a software architect tends to care about different things from a product manager for example. This is the idea of gradual specification - I should be able to defer some decisions to the AI and exercise full control over other aspects, but it's the humans that should be able to choose what level they want to work at.