Lots of interesting stuff in your post!
First, his bill relied largely on taxation, rather than printing money. Not sure how much taxation is left in it after Manchin/Sinema opposed every type of tax, but then they also cut spending by more than half.
So, instead of your $10tn (which it never was), it's gone from 6tn (his opening bid) to 3.5tn (his compromise) to 1.5tn (now), and with a strong prospect of further cuts or total abandonment. So, if he gets his way, it's 15% of what you claimed, and it's over 10 years, and some of which is from new revenue rather than printed... you're playing *really* loose with numbers for a Wall Street guy!
Next, he, Manchin, Trump, Biden, all have constituencies. Trump lost but has not fecked off and is doing a good job of leading his constituency of energy companies, small business, religious people, and suburban and middle-aged/old people. Bernie too has a constituency which it's his job to represent (though I don't think he's doing a good job) - young people and unions. Manchin's constituency is West Virginia centrists, pharma companies, and coal mining companies and ex-workers. He is great at representing them. Sinema represents Arizona centrists, pharma, energy, and small business. Also a great leader for them.
Just because Trump lost, or because Bernie/Sinema/Manchin aren't the leader of their party, they should vanish? No, they represent permanent interests, larger than an election.