Long wait at bank!

Just wondering ,why do banks have so many teller windows when only a few are used. Every time I go to my local bank I have to stand and stand in line and see at least twice to three times as many closed windows as ones that actually have tellers at them.

So I have wondered why even have that many if they never intended to use them? any
ideas? oh yes I could go to the ATM machines but again there isn't place to put my purse or bank book or ATM card while I am pushing buttons. And like most people I only have two hands. Also I have to use a quad cane to balance myself, so going to a teller window is easier for me if I do not have to wait in long lines for a half hour or more. Rant over.