front-end JS can easily also become very complex
I think a better metric is how close you are to reinventing a wheel for the thousands time. Because that is what LLMs are good at: Helping you write code which nearly the same way has already been written thousands of times.
But that is also something you find in backend code, too.
But that is also something where we as a industry kinda failed to produce good tooling. And worse if you are in the industry it's kinda hard to spot without very carefully taking a hounded (mental) steps back from what you are used to and what biases you might have.