I will give it 3 months of the GOP blocking literally everything before Sinema changes her mind.
Why would she?
It’s not like she’s committed to any actual policy goals.
She's definately on the more conservative end of the Democratic caucus, but that doesn't mean she's a Republican or someone who wants Biden to fail, miles from it. The flip is true for people like Murkowski, Romney, and Susan Collins. There are reasonable reasons to be resistant about eliminating the filibuster, and that's a very reasonable position to have, but at the end of the day, we will need to find a way to break out of this deadlock. Just because a Democrat isn't lockstep on every issue doesn't automatically make them a Democracy hater or traitor to the party, and IMO, that sort of view is what will lead to simillar tribalism as to what happened to the GOP in recent years.