Yeah traditionally, real faces are used to make moulds.

Then for fx stuff, the sculptist uses a cast model of the face to make the fx latex pieces of masks or whatever to fit on that person's face.

High quality ones , anyway. When it's tailored for the persons face it fits better and looks better.

There are a ton of videos on how this is all done. I always liked watching videos on movie magic. So that's how I know the basics.

But I can say that almost always, when a likeness of someone is needed, they make the prop from making moulds from the actual person's face.

That's the best source.

3d printing itself , introduced artifacts and errors. So it's not really the best medium.

Even madame tussauds waxworks starts with moulds made from the people's faces (people who are alive anyway).

Fun fact. Michael Myers from Halloween movies wears a William Shatner latex mask. Made from a cast of his face.