RBE doesn't mention PathBuf anywhere. A programmer at my work asked:

"Why PathBuf? Just why generally. I started out using it where I thought it made sense, now I just pass &str. Things like .extension() returning an OsStr mean I just use .ends_with() instead which sort of does the same thing (but not always)"

Steve suggested mentioning that between String is to str as PathBuf is to Path.