...Besides, we can migrate the blockchain over to SHA512 with a hard fork a heluva lot easier that the bank's 40 YO computer networks can upgrade. ...
Caveat: SHA256 broken==blockchain corrupted--your BTC transferred ta hax0r's wallet--irreversible. You can hardfork the ashes all you want, your money's gone. Poof! Fini.
With "legacy" banking? Lol, not much happens. A few delayed/reversed transactions, a bit more boring old paper money, a few hax0ring scumbags lined up against a wall & shot for their faggotry
BTW, what happened in Y2K? Did I miss something? I mean, other than all those ICBMs accidentally Atlantis into smoking molten glass?