there are some html files in the theme folder root (index.html, error pages sometimes)
then there are resources folder
a scripts folder
a styling folder (where half the files in there get compiled from the sass (but where you still need to maintain your fonts)
and a folder with core altas files (although if you update atlas you update all of themes)
this whole folder has no logic to it, and you know how it works because you know how it works, making it unintuiative for new people to learn, and difficult to maintain.
I'd like to see the folder stcutrure broken down into more manageable and logical sections that could be updated individually, maybe even set globally somewhere (if you have your own errror pages, or login page defaults)