Since they don’t wear ties, the button-down look is more formal. And since they don’t wear ties, they can buy bigger shirts.
And that is only at “full dress” mode- equivalent to wearing a tie for more “modern” styles. In less than “dressed up” mode (equivalent to American men not wearing a tie), the button gets undone.
Note that the closed neck (buttoned collar) as an alternative to wearing a tie is no limited to Jews, but is also found among goyim in dress situations where men don’t wear a tie (e.g. the dress uniform of the Marine Corps).