A GFI device on a 220v split phase power supply does not need a neutral but ALL circuits need a proper ground.
A clarification there is needed.
If you're talking about legal stuff, perhaps that is true everywhere, that "codes" these days require grounds for safety.
Otherwise the opposite is true, NO circuits need a ground. Absolutely none at all. All any circuit needs is a RETURN path. That does NOT ever have to be a ground, but of course return circuits can be grounds or even a single ground for many circuits.
I have noticed on my Zero motorcycles, the headlamp negative is NOT grounded anywhere and you will measure zero volts on the headlamp hot to ground when the lamp is on nice and bright. It runs it's own negative wires for the 12 volt stuff, not grounded anywhere.
AFAIK, there are NO grounds in EVs for the battery as that is one place grounds can be more dangerous than not having a ground. A ground for while charging, however, is the norm, but again only for safety.
-Don- Auburn, CA