Patrick Horan of the Mercatus Center argues that the money supply still matters:
In the 1960s and 1970s, many economists thought the money supply was very important for explaining changes in the economy. Perhaps most famously, economists Milton Friedman and Anna Schwartz argued that the Fed caused the Great Depression by allowing the money supply to collapse in the early 1930s. Although the Volcker Fed ended the Great Inflation by bringing down money growth, later research from the 1990s suggested that the relationship between money and other key variables such as output and inflation had broken down by the 1980s. This later research is what informs central banks today.
This contemporary view, however, is based on a faulty premise.