@tante this will depend a lot on the definition of "writing" and "lines of code". If you count individual characters, autocomplete probably has been "writing" the majority of code for quite some time. Lots of autocomplete functionality gets meshed in with LLMs these days, and so, without representing any major shift in the way we write code, you can massage the statistics to make it look like AI is "writing" a lot more code than we would otherwise say.

In the end, a lot of writing code is about the code that isn't written, and hand edited automatically generated code has been with us pretty much since the time text editors were powerful enough to support it.