The blog author didn't think so, but there's good anecdotal + empirical evidence that working with LLMs boosts *overall productivity*. (A recent study: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5188231)
If you lose 8 hrs to weirdness, but save 10 hrs somewhere else, then yeah it does pay for itself.
My argument is that it doesn't need to improve overall productivity much to have positive ROI. Whether you agree that these tools improve productivity or not is another question.