Earlier quoted context omitted.
Yep.. I much prefer 2000 lines of code in one function with very little calls. Easier to reason about, less bugs, easier to maintain. It's very easy to indicate when a new part is coming, just enter a big comment block of what you're doing.
This is the perfect example. You start out like that and all is fine, but two years, a few changes and some bugfixes later your now 2700 line method is a total zombie. The comments blocks are lying and you have incromprehensible dependencies. More over you have to read it all every time you make a change in the method, its inputs or understanding its output. That just screams 'refactor me!'. The exceptions of course…
If you want logical separation, add sub-blocks to the function. You can see things as being a spectrum from fully inline code, to code blocks, to anon functions defined in the function, to true functions.