> You must sell [some of] your assets to feed hugry monster called government [which runs the courts, police, and military which all exist to protect the rest of your assets].
Some assets are only sellable atomically such as art or a house. A government demanding more money because the thing I purchased with taxed money has become more valuable (or not become worthless) is a form of financial gluttony bordering on demonic.
Fiat currency is a tool created by governments to accomplish goals. Massive income inequality generally conflicts with most liberal democracy's goals. Taking loans against unrealized gains lets people much richer than me pay a much lower effective tax rate.