My major issue with your position is that, at least in my experience, good software is the sum of even the seemingly low risk parts. When I think of real world software that people rely on (the only type I care about in this context) then it's hard to point a finger at some part of it and go "eh, this part doesn't matter". It all matters.
The alternative, I fear, is 90% of the software we use exhibiting subtle goofy behavior and just being overall unpleasant to use.
I guess an analogy for my concern is what it would look like if 60% of every film was AI generated using the models we have today. Some might argue that 60% of all films are low stakes scenes with simple exposition or whatever. And then remaining 40% are the climax or other important moments. But many people believe that 100% of the film matters - even the opening credits.
And even if none of that were an issue: in my experience it's very difficult to assess what part of an application will/won't be low/high stakes. Imagine being a tech startup that needs to pivot your focus toward the low stakes part of the application that the LLM wrote.