sight gives you the ability to set up a field of damaging/disabling surfaces before enemies can see you, while you can see exactly where they are.
hearing gives you the ability to detect hidden enemies. I've seen it work several times now.
then there's the sight range for bows (not really applicable to magic, since its range is so limited already). max bow range is 26, normal sight range is 18.5. being able to shoot 7 squares further? actually has come in handy in several fights.
so, not pointless. just depends on your playstyle.
