It impossible for a bank for example to put all their money into Dogecoin because someone got a hunch that Musk will tweet about it. To do that they will need to create some kind of instrument that allows others to bet on Musks tweeting habits.
> There really is no need for the charade of banks now that electronic databases are very solid technology. Their whole role in transmitting and keeping an account of money is surely reproducible
That's not what banks do. You can do that without being a bank, like PayPal did. Most places will have different and much lightweight regulations than banks for this and you will go to jail if you do anything more than holding and transmitting customer money.