

Historically, the Senate has a tradition where the Senators from the state submit a “blue slip” with their opinions on it. If they don’t submit one, it can delay a hearing or kill the nomination. https://en.m.wikipedia.org/wiki/Blue_slip_(U.S._Senate)
Whether it matters changes all the time — see the history part of the Wikipedia article’s History section — but other Senators want theirs respected so sometimes it does. If nothing else, it can give a Senator who doesn’t want the nominee cover from bucking party leadership.
It’s definitely going to put sci-fi authors who write about A.G.I. out of work or at least make them add 1,000 years to their timeline.