I do know how Congress works. There was a reconciliation bill in the lame duck that passed and could have increased the debt ceiling. It also doesn't require a 2/3 majority for a non-reconciliation debt ceiling increase. It would require 60 votes to break the filibuster, which, last I checked, is less than 2/3 of 100. Additionally, Democrats could have eliminated the filibuster for debt ceiling increases if they weren't so dedicated to losing. The Senate Rules are whatever the majority of the Senate wants them to be, which means as long as they have 50 votes and the VP, they can do whatever the hell they want within very limited Constitutional restrictions. The only things that require a 2/3 majority in the Senate are expelling a Senator, treaties, impeachment convictions, constitutional amendments, and veto overrides.
There's also a very strong case for the debt ceiling being unconstitutional since it conflicts with the 14th Amendment, which states that all US debts shall not be questioned. Unfortunately, Joe Biden and his Treasury are too cowardly to pursue that action for the sake of "norms." That leaves Minting the Coin, which would be the Treasury minting trillion dollar platinum coins, which is allowed by statute and would effectively nullify the debt ceiling, even if the administration didn't want to pursue the 14th Amendment strategy.
Joe Manchin, Kyrsten Sinema, and others would rather protect the norms of the Senate than actually accomplish anything with a Democratic trifecta. It's why Dick Durbin allows Republicans to block Joe Biden's judicial nominees by honoring their blue slips, which will ensure that Republicans have plenty of seats to stack with more insane rightwing judges the next time there's a Republican president. That's why the 5th Circuit and 11th Circuit are packed with insane judges who keep producing absurd rulings.