[Dylan16807]

Let's be careful about what scenario we're talking about.

> You can't make 1000$ appear on my bank account and say " you now have a debt of 1000$ to me". You need to give me physical money. But bank can create this money they don't have.

This scenario doesn't involve real money at all. It's just two IOUs in opposite directions. You and I could make such an agreement trivially.

> I think it can lend it up to 10 times the money it has in its vault (not sure about the exact amount)

So this involves real money. But it's not a special bank power. You can loan a friend some cash, which they give to you for safekeeping. Then you can loan another friend the same physical dollars, which they also give to you for safekeeping. Then another, and another...

Now you have $10k in cash deposits even though there's only $1k in physical cash.

The only reason you can't do it in practice is that nobody wants to give you their money for safekeeping. You don't lack the ability to multiply money. You lack anyone handing over money to do it on.