Right. If working with other people, a global gitignore is probably most sensible if you you have say an uncommon editor that likes to create a subfolder with m

Right. If working with other people, a global gitignore is probably most sensible if you you have say an uncommon editor that likes to create a subfolder with metadata, or has a weird convention on temporary in-place rename file names. In those sort of situations, adding the paths from your weird setup to every .gitignore file you work with might be overkill, and potentially unwelcome by maintainers of some projects you work on. But for more common stuff like visual studio cruft in a windows C++ or .NET project, or the python cache folders in a python project, etc., it probably makes more sense to have that stuff in the repository level .gitignore.