Switzerland doesn't have property taxes, so it's better to think of the imputed rental tax as a more progressive implementation of a property tax. Low earners pay less tax on a home of the same value than high earners. And the tax is less distorted by asset price bubbles, since you're taxing the imputed rent instead of the market value.

Now it's abolished, owner-occupied homes will mostly go untaxed, while investor owned ones will be taxed just as before. This is distortionary, but it seems politically infeasible to also abolish income tax on investment income.