The usual argument for the filibuster is that it prevents the majority from simply steamrolling its agenda: if every piece of legislation only needed a simple majority to pass, then in the current Senate, 51 Democrats (including VP Harris) can, if they’re united, do anything they want, and ignore the 50 Republicans. Clearly, that’s not ideal. There should to be a mechanism to prevent that, at least in important cases.
At the same time, Americans elect Senators to actually get stuff done. If Americans elect 59 Senators from party A, and 41 from party B, it’s because they want to advance party A’s agenda, and have it completely thwarted by party B is also not ideal.
But that’s what we have now: Senators don’t need to do a talking filibuster like Jimmy Stewart in Mr. Smith Goes to Washington. All they need to do is send email announcing their intention to filibuster a bill, and that bill effectively requires a 60-vote supermajority to pass. The Constitution reserves supermajority requirements for extreme situation, because the founders realized the need to balance fairness with getting stuff done; there’s a reason they switched from the Articles of Confederation to the federal constitution.
If, as is often claimed, the purpose of the filibuster is to promote compromise, then a better way to reform the Senate rules might be to guarantee the minority party(ies) certain rights, like being able to propose amendments, or introduce some legislation that the majority party doesn’t even want to consider. I’m open to the idea that it might be a good idea to preserve the talking filibuster, for those cases where one or a handful of Senators feel so strongly about an issue that they’re willing to pay a personal cost to block it. But blocking legislation shouldn’t be routine.