Well, the point is by steering it you can get both more expected/reproducible output, and you can correct bad assumptions before they become solidified in your codebase.

You can get pretty close to reproducible output by narrowing the scope and using certain prompts/harnesses. As in, you get roughly the same output each time with identical prompts, assuming you're using a model which doesn't change every few hours to deal with load, and you aren't using a coding harness that changes how it works every update. It's not deterministic, but if you ask it for a scoped implementation you essentially get the same implementation every time, with some minor and usually irrelevant differences.

So you can imagine with a stable model and harness, with steering you can basically get what you ask it for each time. Tooling that exploits this fact can be much more akin to using an autocomplete, but instead of a line of code it's blocks of code, functions, etc.

A harness that makes it easy to steer means you can basically write the same code you would have otherwise written, just faster. Which I think is a genuine win, not only from a productivity standpoint but also you maintain control over the codebase and you aren't alienated or disenfranchised from the output, and it's much easier to make corrections or write your own implementations where you feel it's necessary. It becomes more of an augmentation and less of a replacement.