I think it was complete bluff, and Biden probably knew that but the reality is he’s pro-austerity. He can’t say it outright since it’s unpopular, but he’s still quite conservative and believer in the economic/corporate status quo. It might be deliberate, or it might be that he’s literally just not imsginative enough to see outside his own bubble.

i don't see how you can make this argument when he's presided over the largest expansion in social spending since the Great Society and has approved something in the ballpark of 4 or 5 trillion dollars in new spending between stimulus bills and his political priorities. a serious debate in the Democratic caucus was over whether to spend "just" 1.75 trillion or go for 2.2 trillion in spending. if this is austerity the word has absolutely no meaning at this point.

You have to ask yourself if the GOP really would’ve plunged the world into economic armageddon just for a handful of aid concessions

Yes. They would rather Biden look bad than America look good.