Well, yes. For instance, Finland, where I live, has a very much simplified income tax collection procedure. Deductions for people with children have been eliminated. Deductions for mortgages are being eliminated. All this in the name of simplicity and, yes, fairness.

After all, if you can afford a mortgage, you are clearly well-off, so you should be taxed more.

(And there is a good point: Mortgage deductions distort the housing market. But rent subsidies distort it even more.)