Inflation is tax on two layers. It makes you lose your purchasing power because of rising prices. It is like 5% p.a. Inflation taxed all your static fiat wealth 5%. It's more complicated, because the average number is not how prices of goods and services you buy change, it's just some bureaucrat's calculation based on what they think people buy.

Then there's another tax on top. Imagine you invested 1 million usd in a business and made 1.2 million usd at the end of the year. You are taxing income of 200k. But that is not income in real terms, because in order to buy something that was worth 1 million you would need 50k more if inflation is 5% (it isn't, but for illustration). So you are taxed on the incompetence of the central bank to keep the value of money.