It's only the banks which earn profits by lending our invested money as loans for interests.The only benefit which we could get is that our investment remains safe but not safe from deflation.
It will be good to take loan from banks and invest in crypto so this way you can get benefit from bitcoin but as you are saying our money will remain safe in banks so it is not true because your money will remain safe but it will be useless and will not give you any kind of profit, if you will invest in bitcoin then your money will increase more and more so this way your money will increase along with highly safe and secure in bitcoin wallet so I prefer to use bitcoin than banking system.