Human eyes aren't placed like that for a greater horizontal viewing angle. We've only got about 120 degrees horizontal, compared with say, a pigeon that has about 340 degrees horizontal. We've got eyes placed like that so that we have stereoscopic vision - which covers about 100 horizontal degrees in front of us.
Vertically, we've got about 90 degrees - so the actual "good area" of stereoscopic vision where we can easily focus is a slightly vertically squashed ellipse. So 4:3 is actually a better match than either 16:10 or 16:9.