An individual function can quite reasonably be 500 lines long. A giant case statement handling routing is one example. More controversially, if I am gong to need to do a lot of ugly compatibility hacks then I prefer to consolidate them and thus keep most functions clean.

Cyclomatic complexity is one of the more well-rigorously studied measure of code quality, I don’t know if I’d pick that hill to die on.

It's rigorously studied but it's a crap thing to put an arbitrary restriction on, because it doesn't correlate well enough to warrent that. If you put a restriction on it, bad code still gets through fine while some good code gets made worse to bypass the checks (the biggest one is large switch statements acting as dispatch: Perfectly understandable, but if you split such a thing into multiple functions magically the cyclomatic complexity goes down to satisfy the linter but the code has just gotten harder to understand for static analysis and humans alike).

A function can be five hundred lines long without having high cyclomatic complexity.

The average size of functions is independent of the programs total cyclomatic complexity.

John Carmack, the famous Id Software programmer, tried it out for a few thousand lines of space rocket code, and he liked it. He argues why giant huge functions can be good for maintainability:

http://number-none.com/blow/john_carmack_on_inlined_code.htm...

Previous HN discussions about that:

https://news.ycombinator.com/item?id=12120752

https://news.ycombinator.com/item?id=8374345

https://news.ycombinator.com/item?id=18959636