As someone who's worked with both more fragmented/modular codebases with smaller classes and shorter files vs ones that span thousands of lines (sometimes even double digits), I very much prefer the former and hate the latter.

That said, some of the models out there (Gemini 2.5 Pro, for example) support 1M context; it's just going to be expensive and will still probably confuse the model somewhat when it comes to the output.