krupski:
Why do you want to do that?
Because it allows you to quickly navigate the code instead of needing to scroll through hundreds of lines every time you need to find something.
krupski:
It seems like splitting up your code into so many different files will do nothing but create a testing and debugging nightmare.
Why would it do that? The Arduino IDE just concatenates all the .ino files together before compiling so to the compiler it's no different from your thousands of lines of nightmare monolithic .ino file.