I think there's some value in pure vibe coding. To your point though, the best way to extract that value is to know intimately at which point the agents tend to break down in quality, which you can only do if you read a lot of their output. But once you reach that level, you can gain a lot by "one-shotting" tasks that you know are within their capacity, and isolating the result from the rest of your project.

How often do the AIs devolve at some task? Or does switching models make those assumptions inaccurate?