I'm very much on the left, but I can see a benefit to the sunset bill, as a heartbeat to ensure liveness of the legislature. Congress has been profoundly gridlocked this decade, but they absolutely must keep reauthorizing the budget, or the nation grinds to a halt. Although we've had a few short government shutdowns caused by this, passing a budget has been effective at forcing all parties to sit down and vote together. It guarantees at least one bill passes.