A lot of high end restaurants have very small fast rotating menus. 5, maybe 6 items. It’s a good system. Exactly why you say: focus. Focus your staff, your stock, your efforts. Big menus are a warning sign. Except for Cheesecake Factory, somehow they’re pretty good with a huge menu. Never figured out how they pull it off. Guess every rule has an exception.
Of course, that mortifies my wife.