I agree with both statements, but that doesn't change the problem I stated. If an agent produces reasonable code 80-90% of the time, and 10-20% of the time it makes mistakes that could render the codebase irretrievably unevolvable once they accumulate, the only thing you can do is to carefully review the agent's output 100% of the time. That it gets things right 80% of the time as opposed to 40% of the time doesn't change this calculus one iota.

But agents generate code much faster, and to know slow them down, some people want to not do the only thing that can currently ensure you get good results, which is to carefully review the output. Once that happens, there is simply no way for them to know how good or bad what they're getting is.