I know what you mean, but I also hate using lines of code per day to measure productiveness, and I hate it when managers in corporations look at number of lines added in PRs to measure how productive a dev is.
I was going to say "start of coding" but some tasks are just so boring that I may procrastinate on starting it. That also indicates an element of difficulty (in giving a shit), but not what we're trying to measure here.
I discovered the Mikado Method quite on my own as a consequence of trying to tackle increasingly complex cases of 'large-scale' or 'top-down' refactoring before accepting that as the oxyest of morons. I was sold when I realized that when you finally discover the crux of the problem, the 'Rome' that all roads lead to, between half and 80% of the code you just wrote isn't strictly necessary. Throwing it all out wholesale is how you avoid code hoarding. Yes, once in a while you go out to the proverbial trash can to pull something back out that you actually did need, but the tabula rasa aspect is profoundly useful psychologically, especially for that 'tax' bit I mentioned above.
There is always some function in the middle of the call tree, that if you add or change the meaning of an argument then the feature or bug fix becomes a logical conclusion of that new semantic. Either the code above it or below it hardly needs to change, decoupling the feature from all but a handful of functions/concerns.
A bad programmer will happily plow through adding a new argument to fifteen method calls and then propagating that change to a hundred call sites. And that code will be buggy as hell because their coworkers have already written them off. If it's too much code for others to review, you can be sure there are bugs in it. And if you didn't listen the last ten times people told you to stop writing so goddamned much code, you aren't going to listen this time, either. So have at it, sport. We'll just make sure you get the blame for the bugs, until someone in management wakes up. If they don't, then they see that the sections of code people "won't touch" but you will are getting bigger, and mistake your ownership of this code for a sign of prowess instead of a sign that you are inspiring apathy in others.