Sure they do: it’s easy to get 10x gains if you were only producing 0.1x before.

This is what I'm seeing - for people who were slow and didn't posses a lot of depth or breadth, their blast radius and impact has skyrocketed. They can now work in unfamiliar domains quickly, without any knowledge of the nitty gritty details of those domains!

For me personally, it's a tradeoff of generating the first pass code 10x more quickly, but then deeply knowing and validating the code is then 10-20x more work than it would have been if I'd written it myself (and if time is of the essence, then there's the option of shallow validation/understanding in exchange for speed - which is a compromise in rigor and path towards tech debt). In the end, none of this seems like a net win (unless you don't care about quality), and it is much less enjoyable.

TL;DR; While LLMs are faster to spit out first pass code, by the time I've validated and fixed the LLM's first-pass work, I could've had my "by-hand" implementation done correctly, and had much deeper understanding out of the box. Net loss.