You're acting like the government invented inflation; it didn't. Before central banks, inflation fluctuated freely in the economy, sometimes very high, sometimes into significant deflation. This volatility exacerbated other economic or financial fluctuations, causing a lot of problems. The goal of central banking is not to introduce or create inflation, but to manage it for greater certainty in long-term investment. A steady 2%/year inflation is a stable currency.

If you think it's bad knowing that your dollar will devalue 2% every year, imagine trying to make plans not know whether it was going to drop or go up 7% next year--or anything in between.