U.S. dollar value decrease over time as many investors already know it and claim cash is garbage. Based on some data, U.S. dollar has lost its value over 90% since 1913. The cumulative inflation of U.S. dollar since 1913 is 2,900%, This is the result by cumulative inflation over time.
But It is nonsense to blame dollar as the value decrease. Because it is not gold or diamond. It is a currency that has the role of blood of economy.
Moderate level of inflation(2~3%) could boost economy. Investors may try to invest on more productive activities or development instead of just keeping the money. Because the money value decrease with inflation rate.
Dollar's inflationary nature makes borrowing easier that may boost economic activities.