You make a good point, but I only agree partway. You are right that if a factory builder was saving money to build a factory, then inflation hurts his output.

You make a good point, but I only agree partway. You are right that if a factory builder was saving money to build a factory, then inflation hurts his output. However, if a factory builder takes on loans to build a factory, then inflation actually helps his output! I would expect that most factories are built from loans, rather than savings. In general, banks are creditors and businesses/people are debtors. So perhaps inflation hurts the banking sector but helps other sectors. Lastly, inflation only hurts the factory builder if he's using money as a store of value. If he buys stocks/bonds/commodities, then he can store value without exposing himself to the risk of inflation. What do you think about these points?