A way worn by being walked. Not built - a path is the record that others went first.
Old English pæth (a path, track), from Proto-Germanic *patho-, of disputed and possibly non-Germanic origin, perhaps borrowed from an Iranian source akin to Avestan pathi- (way); a way worn into the ground by the record of others having walked it first.
A way worn into existence by being walked, rather than built — the record of everyone who went first, left as ground.