The problem is that LLMs do not have a conceptual grounding in actual time. They estimate based on statistical correlation found in their training data which is filled with standard corporate project management timelines legacy codebases and waterfall estimates.

This is very common as they have no conception of time. They are just using ballpark figures based on what they see in the wild. I see estimates for modules in weeks/months when it can produce it in a single afternoon of prompting.

You ask LLMs for estimates? Interesting.

Probably big model providers should do calibratuons for that and add an estimation skill.

They tend to turn a small change into the whole cleanup plan. Sometimes that is useful, but it makes estimates too large.