The cost of code never lived in the typing — it lived in the intent, the constraints, and the reasoning that shaped it. LLMs make the typing cheap, but they don’t make the reasoning cheap. So the economics shift, but the bottleneck doesn’t disappear.

For most non-hobby project, the cost of code was in breaking a working system (whether by a bona fide bug, or a change in some unspecified implicit assumption). That made changes to code incredibly expensive - often much more than the original implementation.

It sounds harsh, but over the lifetime of a project, 10-lines/person/day is often a high estimate of the number of lines produced. It’s not because humans type so slow - it is because after a while, it’s all about changing previously written lines in ways that don’t break things.

LLMs are much better at that than humans, if the constraints and tests are reasonably well specified.

> LLMs make the typing cheap, but they don’t make the reasoning cheap.

LLMs lower the cost of copy/pasting code around, or troubleshooting issues using standard error messages.

Instead of going through Stack Overflow to find how to use a framework to do some specific thing, you prompt a model. You don't even need to know a thing about the language you are using to leverage a feedback loop.

LLMs lower the cost of a multitude of drudge work in developing software, such as having to read the docs to learn how a framework should be used to achieve a goal. You still need to know what you are doing, but you don't need to reinvent the wheel.