Demand-Supply the same economic-activity...

Though Monetary Policy is said to be a tool to control demand during high inflation and full employment, but it also decreases supply due to higher borrowing cost lower investment and higher unemployment which reduce supply.

During high inflation it is best to cut rates to increase supply due to higher prices which would contain demand and prices. For businesses higher prices, lower interest rates are good for investment and increase employment and profits.

If we have reached full employment higher wages would help contain employment and demand and a zero interest rate would help increase investment and supply and growth.

Demand and supply are different names of the economic activity when both increase prices, interest rate and wages increase and when both fall prices, wages and interest rate fall.

Laissez faire or free market or the invisible hand philosophy or ideology is true in the long run, few years, even Keynes proposed government intervention to increase employment during underinvestment by the private sector, lower prices, wages and interest rate and liquidity trap in which interest rate cannot go below zero.

In this situation inflation could lower real interest rate but would also reduce real wages and demand which together means lower demand and inflation further, however lower prices due to zero interest rate would help increase employment and demand and investment and supply and inflation faster, Pigou. Public investment/employment might help recover fast.