A savings account isn't cash, its an immediately-callable loan from the account holder to a financial institution; for the account holder, it provides an asset with very good liquidity (but perhaps marginally worse than that provided by a checking account), essentially zero risk, but poor returns (but perhaps marginally better than that provided by a checking account). Its a way of meeting short-term spending needs (but perhaps slightly longer term than that met by a checking account).
Demand deposit accounts (both checking and savings) in general are, like cash, basically for short-term spending, but where the bank provides some benefits (actual storage, along with access mechanisms more convenient for many uses than pulling physical bills out of a storage locker).
Savings accounts are for short term liquidity, not long term stores of value. Long term, look to bonds, stocks, and other asset classes. Money is for spending, not storing.
