The filibuster has essentially become a mechanism to ensure you have a somewhat broad consensus among the states, instead of being able to ram things through with a 51% majority.

Just keeping the lights on shouldn’t require a 60% consensus (it should be the default). This is represented by the reconciliation process, which is some budget related voting process that only requires a majority in the senate. But the reconciliation process was used up to pass the “one big beautiful bill.”

You keep saying filibuster, but it is the “vote for cloture” (similar to a quiet filibuster) which is the thing that has blocked most legislation.

I am curious why Republicans have not changed the parliamentary rules for cloture. The party seems to be pushing states to gerrymander to benefit their Congressional power as early as the next Congressional election. My best guess at the moment is there are a few Republican members who fear what the party leadership does with no opposition party constraints.

Republicans don't want to remove the filibuster because they want to keep it as a tool when they're in the minority and use it to blame Dems for not doing things while in the majority.

Fundamentally, Republicans just want tax breaks and judicial appointments, and the filibuster already doesn't block those. So it hasn't really been a problem for them. Since Dems in theory want the government to work, they can keep things working well enough to let the Dems deal with their time bombs like expiring ACA subsidies and middle class tax breaks.