I think its more likely that llms got better at using harnesses, which help force them to make sure everything compiles/runs before passing back to the user. This caused people to form habits around this where they slowly stopped checking the output.

So people are super impressed because things just work, and they do.. Until they dont.

Just because things compile doesnt mean they're going to hold up, and most of this slop wouldn't, ive seen it first hand and you can also tell by the increased amount of outtages across different platforms.