Manipulation in banking system

so i was recently thinking how manipulative the nowadays banking system is.As far as i see people using mostly cards payment from young to old gen.That means bank literally owns your money what a surprise LOL but the question is since its just numbers in my bank account is there any chance bank moving a cash flow somehow without us knowing that?I heard somewhere that banks using only 10% of deposits of those money that people putted into their account but its was about before the digital banks and shitt.What a chance that in this digital era they could move numbers without you even knowing it until you making a withdrawal ofc. And also if i do a transfer from one country to another like lets say CHF to USD it means bank needs to get a real note to cover those digits or im wrong??