Agree but you are talking about a POC, and he is talking about reliable, working software. this phase of LLM are perfect for POCs and there you can have 10x speedup, no question. But going from a POC to a working reliable software is where most of our time is spent anyway even without LLMS.

With LLMs this phase becomes worse. we speedup 10x the poc time, we slow down almost as much in the next phases, because now you have a poc of 10k lines that you are not familiar with at all, that have to pay way more attention at code review, that have to bolt on security as an afterthought (a major slowdown now, so much so that there are dedicated companies whose business model has become fixing Security problems caused by LLM POCs). Next phase, POCs are almost always 99% happy path. Bolt on edge case as another after thought and because you did not write any of those 10k lines how do you even know what edge cases might be neccesary to cover? maybe you guessed it rigth, spend even more time studing the unfamiliar code.

We use LLM extensivly now in our day to day, development has become somewhat more enjoyable but there is, at least as of now, no real increase in final delivry times, we have just redestributed where effort and time goes.