Ross Douthat says “the filibuster tends to pull legislative efforts toward the center, rather than killing them off entirely.” There’s a certain kind of definition of “toward the center” in which anything that somewhat frustrates the will of the president is, by definition, centrist. But it’s not clear why would we place value on this.
Alternatively, you might think of “the center” as representing the center of public opinion. In that case the policy status quo may be very different from what the median voter wants. And in that case, a president proposing big change is pulling policy toward the center. And efforts to scale back his ambitions are making the new status quo less centrist, not more centrist. Brendan Nyhan spells this out with charts and sums up “the extent to which the national median voter’s preferences correspond with the relevant pivots in Congress will vary over time. There’s no guarantee that the filibuster pivot will be closer to the national median than the Congressional median.”
The important point I would make is that bicameralism and the presidential veto already create a large bias toward the status quo. We had at least one branch of congress controlled by a different party than the one that holds the White House in 1981-1992, 1995-2002, and again in 2007-2008. If you think that things like encouraging bipartisan compromise and trimming presidential policy proposals are important objectives, then America’s “one, two, three: legislate!” method of getting things done serves them well. Adding a supermajority requirement to the mix is just odd, and mostly serves to obscure accountability.