Over time, evolution leads to the selection of new dominant traits that allow a species to survive and thrive. At the same time, other characteristics atrophy or simply reach a point where they become vestigial features that serve no useful or discernible function.
In the era of the permanent minority filibuster, we've just witnessed the latter occur with the sole valuable function of the vice president (excluding his or her role as designated successor to the president) – serving as president of the Senate and breaking ties.
Not too long ago, I remember that it was a big deal when the Veep might have to jet back to Washington to be on hand to cast a tie-breaking vote. Al Gore left the campaign trail leading up to the 2000 election to be ready to do it. Mephistopheles Cheney loomed over some of the close Senate votes when the votes were tight.
With the filibuster firmly entrenched in the Senate (the Republican minority used it 138 times as part of their recent "just say no" campaign) and no value or benefit to bipartisan efforts, the idea that we'd ever have another tie vote in the Senate seems laughable. There's no way a bill that was so close could ever get that far now as the minority would prevent it from reaching the floor for a full vote, simply because they say they have 41 votes.
And so, with the apparent creation of a non-constitutional supermajority rule in the Senate, the office of the vice president effectively loses its sole officially mandated power. The function for which the Veep was intended no longer exists. Joe Biden and his successors, legislatively speaking, have been reduced to a walking, talking, fundraising appendix. He must be so proud.