You do, but even if it's paid for, you still have to pay taxes, insurance, and maintenance on it. It's likely better than renting in most cases, but it's not a free place to live.

It's still an income-producing asset. It produces quite a lot of income. You have to pay for maintenance on everything, but that doesn't mean that income-producing assets don't exist.

Living in a house is not income.

It's imputed income because you don't have to pay rent.

This is the most European thing I’ve read all week. Income is inflow of money, while rent is an expense. The avoidance of expense should not be considered income for tax purposes: it would discourage frugality.

If you applied that principle consistently, it would be much worse to tax income, since that discourages production.

No, that's just a measurement methodology. It's income because it's a valuable product that you receive.

Consider a farm that grows wheat on 15 acres of fields. Are those fields an income-producing asset? If so, your house is also an income-producing asset.