Egyptians hieroglyphics are phonograms though, not [very loosely defined] ideograms -- I thought that was the point about their translation, that people wrongly assumed they were pictorial ideograms.
As the other comment said, why can't they be complementary? Emojis are great for handling subtext and seem to (partly) offer a solution to Poe's law. That being said, I too can't take anyone who uses emojis in his comments seriously.