bitcoin cannot replace the banks. The people some people use bitcoin not a bank when transfer money is laundering black money. That's all. Maybe another blockchain coin will replace the banks in future but I pretty 100% sure, not bitcoin.
Look easy for money laundering when using bitcoin because transaction is hidden and not one know how bitcoin wallet address detail, you can see if corruption understand with bitcoin looks easy how to make money laundering and without any way to detected who is sender and receiver from bitcoin fund, but so far they not understand how to make money clean from corruption and always try to buy some thing could be know by public.