Comment by socalgal2
TIL: font designs are not copyrightable in the USA. Font files are but the design itself is not. It seems you are free to copy the design, but not the file. Not sure how that plays out in practice. Is it common to copy a font design or is it just more common to be inspired by a font design but make a new font that's in the same general design space? Like say Arial seems inspired by Helvetica but is not the same.
There are definitely fonts that are nearly identical copies, e.g. Palladio is a clone of Palatino (https://en.wikipedia.org/wiki/Palatino#Free_and_open-source_...)