That’s the fact:
Once a deposit is made at the bank, it’s no longer your property. It’s the bank’s.
What you own instead is a promise from the bank to repay. It’s an unsecured liability. That’s a very different thing from owning physical cash stuffed under your mattress. Yet, 99.9% of people conflate the two.
Cash deposited into the bank technically makes you a creditor of the bank. You’re liable to get burned should the bank make a bad bet and get into trouble. The risk is not insignificant. Most banks gamble with their customer deposits on risky investment fads like mortgage-backed securities.
The lie about to whom the deposits belong. It’s an credit and so you never do savings in a banking account you always do investing.