[anonym29]

The problem with hacking is that it's far easier to patch a vulnerability than it is to redesign a currency note and reissue new batches of them across an entire printing press while removing the old ones (some real, some fake) from circulation very slowly.

Also, Bitcoin has never had the counterfeiting problem of currency notes, largely because there's no such capacity for bad actors to create or issue counterfeit Bitcoin, as Bitcoin backed by mathematical work that must be performed to in order to mine/"mint" new Bitcoin, unlike US Federal Reserve Notes, which are backed by nothing more than an Intaglio printing press, some engraving plates with publicly-available designs, and 3D security ribbons, ribbons featuring ink that is visible under a blacklight (you can find which chemicals exhibit this property on Wikipedia), some paper, and some linen. Oh, and every single one of those ingredients are are produced by a third party (NOT the US Bureau of Printing and Engraving), who all solemnly pinky promise they don't secretly keep and distribute any extras :)