I'm on track to finish my current gig having written negative lines of code. It's amazing how much legacy garbage long running codebases can accumulate, and it's equally amazing how much it can slow down development (and, conversely, how much faster development can become if legacy functionality is deleted).

Pretty much the same. And it's not even about improving the code (which I did), but mostly about removing dead code and duplicated code. Or worse, half redesigns of some subsystem which led to very bizarre code.

When people say coding is slow, that usually means they're working on some atrocious code (often of their own making), while using none of the tools for fast feedback (Tests, Linters,...).