But I would still as a depositor have the promise from the bank that the bank will give me back my cryptocurrency when I want?
If I do, there is practically zero difference how banks would work with crypto and fiat. And that promise can be used as money just like it can now with fiat. Thus banks would be able to monetarily multiply crypto at will as well.
If not, well, how exactly are you planning to stop me and my bank making such a contract? You know, the bank can pay me some interest on my savings is I let them lend the money forward, so both banks amd my incentive is to allow the lending of my deposit.
In practice, there would be 1 big difference: payments are made in cryptocurrency, not in bank credits. And this difference has an impact on all the rest.
We use bank money now because it's more convenient than paying with gold. But imagine that paying with gold was more convenient and preferred. In that case, we would see money in the bank as an investment, not as a wallet.
Your employer does not wire transfers money to your bank, but to your wallet. He pays you "in gold" so to speak. Same when you go shopping etc. There is no bank involved in transferring money anymore.
If you put money on the bank, you cannot use those credits to pay other people, as you are able to do now. Because people expect "gold", not bank credits.
You are correct that in a cryptocurrency world, banks could still have fractional reserves. But the main difference is that there will be a clear distinction between "real money", which is cryptocurrency, and "bank notes", which are a promise of the bank to pay you cryptocurrency. Right now, you cannot make the distinction between the two.
This is also the reason why they were able to let the gold standard disappear, because nobody would notice. If everyone trades in gold, the gold standard cannot just be abolished.
Basically a cryptocurrency world is a gold standard, where gold is the preferred way of paying.
This would also mean that banks will go back to how they operated when there was no central bank. And even further back than that, because payments are more conveniently made with "gold".
Basically everything you just said is already possible with USD instead of Bitcoin. You could demand your employer pay you real cash instead of bank credit, and so on.
The reason nobody does this is because there is no good reason to -- banks in the US are extremely reliable and trustworthy.
I live in Europe, so no, I do not have USD in my bank account.
What if my real employer doesn't live close to me because he's in a different country? Should he send cash in an envelope? Which cash? The one from my country? From his country?
What if you live in Venezuela, would you still trust the government money?
So no, this is not possible with USD bills.
> banks in the US are extremely reliable and trustworthy
"Massive bail-outs of financial institutions and other palliative monetary and fiscal policies were employed to prevent a possible collapse of the world financial system."
In other words, banks multiply money right now, but you cannot multiply cryptocurrency.
It's much more honest and clear.