Been using Linux as my primary OS for (counts on fingers)... decades now. Called them folders the whole time. Never had a problem with it. Nobody who matters cares.
meh. folder is 2 syllables, directory is like 4. I'm lazy. If someone gave me a clear one syllable alternative that others would know what I meant (even if while cringing), i'd probably start using that instead. I've tried just "dir", but no one ever knows wtf i'm saying.
My intuition is that directory is the older term and refers to something existing on the file system while folder can be that but also includes "virtual folders" that group together different files from across the file system like when photo manager shows you categories like 'recently viewed' or 'taken in 2023'.
I mix and match. I used to have an Amiga back in the day, and they were called directories there. As such, most of my parlance is from those days. But most of my work life has been on Windows. So, folder has sneaked into everyday usage.
Directory means a listing. You are referring to the list of names of some items.
I'm usually working with folders that actually contain files and other folders. It's often closed, so the content is not shown. A folder is a container.
Wikipedia clarifies this difference.
A telephone directory does not contain telephones.
I switched to Linux only about a year ago. I frequently called them directories even in Windows. I sometimes use folder too, but usually directory I think.
I have been switching a number of computers over to Linux over the last few months in preparation for the end of Windows 10. But honestly shit like this that makes me think, maybe Windows 11 isn't so bad?