I know I could and should encrypt whole drives but I want another layer of protect specific folders when my devices are unlocked, a password. I want the folders to behave like regular folders where I can add or remove files as usual, without a clunky UX like password protected zips. I looked it up and didn’t find any straightforward solutions.
There may be Windows only solutions to folder password protection (the one I remember is from 20 years ago lol), but they are unlikely to be cross platform.
Of the top of my head the only thing that would work in a cross platform manner are password protected archives.