Except, you don't.
When you deposit money in a bank, the bank writes it as a liability because it owes you that money.
I.e., the money is no longer yours.
Discussion
exactly and its worse than that in that the money you deposit likely isn't real money either but a creation from fractional lending
Imagine lending your money to someone in exchange for basically zero interest, if not actually negative interest because they charge you all sorts of fees for their "services". And, on top of that, they are objectively insolvent to begin with: they have no serious means to pay you back because they're running a ponzi scheme.