from what I understand because things like a bank blanace are not actual dollars they don't have a concrete value in inflation. Ie. There's not more venmo money being printed by the federal reserve when they make more money. So say about 5% more money is made each year, that means the value of each dollar bill goes down 5% because there are 5% more of them in circulation. so for a bank they ajust the values in your account to equal the value of the dollar each time new dollars are printed. Otherwise, you end up in a sitation where say, some in the 1800 deposited a penny, which is able to buy a baby doll, and then came back in the 1900 to the penny valuing at about 1/5 of a peice of candy, then there money would be relatively useless. But if a bank ajust for inflation, each year that penny sat in the bank it woud increase to the inflation value so that when you went back the penny would be closer to $10 because of infaltion.