Well, we created letters as a more efficient way to write pictures, by spelling out the names of the pictures by their sound.

Other languages stayed hieroglyphic.

But emojis are more like accent marks or "asides". 

 but since the computer generates the pictures for us, wouldn't it be more efficient to revert back to hieroglyphs? 

 Still can’t get over HTML not having a <sarc></sarc> tag