The 1911 was not designed as a target gun.  For it's original purpose, sights were a pretty low priority - and it shows!  Notch was just too damn narrow.

If you have good eyes, they are just barely adequate.  If they don't suit you, change them.  It isn't a big deal to do so.

I have a pre WWII 1911 and the sites are lousy.  Too fond of it to change them so when I shoot it, just live with it.  I have others with good sites.  That old warhorse sent more than one German to his reward.  I have no doubt it would do the same, at close range, for any moron foolish enough to try and take it from me.