How does recent use of the filibuster compared to how it was used in the past? how might it be used in the future?

In the Senate of the United States, the filibuster has gone from dramatic to ho-hum in just a few years. Filibuster rules allow a minority of forty-one Senators to prevent even fifty-nine out of a hundred from cutting off endless debate and proceeding to an up or down majority vote. Filibusters used to happen infrequently and mainly on very controversial issues, but nowadays Senators and pundits take it for granted that bills cannot pass without a sixty vote