This is basically a "thinking tax".
If you don't want to think and offload it to llm they burn through a lot of tokens to implement in a non-efficient way something you could often do in 10 lines if you though about it for a few minutes.
If you tell me I didn’t really need a LLM to be able to do all that in a week and just some thought and 10 lines of code would do, I suspect you are not really familiar with the latest developments in AI and just vastly underestimates the capabilities they have to do tricky stuff.
Thats why it took a week with llm. And for you it makes sense as this is new tech.
But if someone knows those technologies - it would still take a week with llm and like 2 days without.
Before LLMs we simply wouldn't implement many of those features since they were not exactly critical and required a lot of time, but now when the required development time is cut signifficantly, they suddenly make sense to implement.